At present, the autumn atmosphere is strong, and the Nine Eyed Tower Great Wall located in Yanqing, Beijing has ushered in the three color mode of the year. Entering the Nine Eye Tower, golden, orange red, and dark green complement each other, and the undulating mountains appear particularly majestic under the autumn sunshine, with the Great Wall hovering among the mountains. The Jiuyan Tower of the Great Wall is located on Huoshan Mountain in Sihai Town, Yanqing District, Beijing. The main peak has an elevation of 1141 meters and is the largest and highest specification enemy building on the Great Wall, known as the "First Tower of the Great Wall". The Great Wall showcases the beauty of the organic integration of historical culture and ecological civilization. In order to protect the unique and magnificent Great Wall, in recent times, under the principles of not changing the original state and minimal intervention, the protection and restoration of the Great Wall have gradually explored the transition from salvage protection to research-based restoration, maximizing the protection of the authenticity, integrity, and ancient historical features of the Great Wall. How to 'repair the old as old' with minimal intervention in the restoration of the Great Wall? According to researchers, the basic principle of protecting and repairing the Great Wall is to follow minimal intervention and restore the old as it is. For example, Jinshanling Great Wall, located in Luanping County, Chengde City, was built during the Hongwu period of the Ming Dynasty, with a total length of 10.5 kilometers, and is known as the "essence of the Great Wall". Along the route, there are a total of 5 passes, 67 enemy towers, and 3 beacon towers. Among them, the text brick wall, Qilin shadow wall, and General Tower comprehensive defense system are known as the "three wonders of the Jinshanling Great Wall", highlighting the characteristics of the Jinshanling Great Wall. The Jinshanling Great Wall is renowned for its well preserved condition. At present, Jinshanling Great Wall has completed three large-scale overall repairs, always adhering to the original prototype, original craftsmanship, and raw materials, and maximizing the restoration of the ancient historical style and architectural features of the Great Wall. The section of the Great Wall from Dajinshan Tower to Yaogoulou in Jinshanling once had a problem of about 50 meters of wall tilting towards the outside of the pass. How to reduce the intervention of modern materials and effectively reinforce protection? Guo Zhongxing, director of the Jinshanling Great Wall Cultural Relics Management Center, introduced that there are thunder stone holes on this side and drainage holes on this side. A cross steel plate is used outside the two holes. If the steel bars are tightened, they will no longer tilt outward. At present, Jinshanling Great Wall has implemented the Great Wall displacement monitoring project, installing displacement monitoring equipment in more than 20 sections of the Great Wall for real-time monitoring. The protection of the Great Wall has shifted from salvage protection to preventive protection. Guo Zhongxing, Director of the Jinshanling Great Wall Cultural Relics Management Center, introduced that in the future, we will digitize all sections of the Jinshanling Great Wall, using aerial survey modeling and 3D modeling to provide more scientific and accurate basis for the protection and restoration of the Great Wall in the future. The 10.5km Jinshanling Great Wall, which gathers almost all the architectural forms of the Great Wall of the Ming Dynasty, is the essence of the Great Wall. It is still magnificent and picturesque after weathering. What modern technological means are available to protect the Great Wall? Shanhaiguan is the first pass at the eastern end of the Great Wall, located in Hebei Province. Among them, Sandaoguan is the most dangerous section of the Shanhaiguan Great Wall. The stone built Great Wall meanders down from the cliff top like a swimming dragon, and then rushes up against the mountain back, forming an inverted posture, which is extremely steep. Aerial photography technology has shown great skill in the overall investigation and subsequent inspection and protection work of the Great Wall. In addition, the towering Great Wall winding through the rugged mountains cannot escape the erosion of rainwater. Monitoring data shows that the erosion and erosion caused by rainwater can cause significant damage to the rammed earth Great Wall, leading to soil cracking, formation of holes, and ultimately resulting in wall collapse. Through long-term field investigations, experts have found that algae growing on the surface of soil layers have a significant protective effect on rammed earth walls. After screening and identifying various algae, filamentous blue-green algae were identified as capable of forming effective biological soil crusts. After scientific cultivation in the geological laboratory, it has now been successfully expanded to the surface of the rammed earth Great Wall. Liu Liang, director of the Geotechnical Innovation Center of the 8th Geological Brigade of Hebei Provincial Bureau of Geology and Mineral Resources, said that the grayish green biological soil crust can effectively prevent rainwater erosion. Filamentous blue-green algae can effectively wrap and entangle with soil. Meanwhile, filamentous blue-green algae can secrete polysaccharides, which can effectively bind soil particles and form a spatial network structure, protecting the rammed earth Great Wall. In addition, patrol robots can independently walk in the walls and enemy buildings of the Great Wall, integrating advanced technologies such as 360 degree imaging, LiDAR, and infrared monitoring, which will effectively improve the efficiency and quality of Great Wall patrols. Liu Liang, director of the Geotechnical Innovation Center of the 8th Geological Brigade of Hebei Provincial Bureau of Geology and Mineral Resources, said that this quadruped robot can effectively replace manual work. The first time reaching a point, a three-dimensional structure can be scanned by a laser radar. When conducting a second inspection, if there are any signs of detachment or cracking, comparing the data from two laser radars can effectively identify the problem. How to respect the original style of the Great Wall according to local conditions? The Great Wall has diverse forms and preservation conditions, and our understanding of its protection is constantly evolving. How to respect the original style of the Great Wall according to local conditions? Liu Wenyan, Deputy Director of the China Academy of Cultural Heritage and the National Cultural Park Protection Research Institute, introduced that the construction concept of the Great Wall is to adapt to local conditions, with different materials used in different places. So, respecting the original appearance of the Great Wall, the restoration adheres to the principle of minimal intervention, which is to try not to move or change the current state as much as possible. If a part of the Great Wall is intact, it is intact. If it is damaged, try to avoid new risks as much as possible. This is the greatest respect for the Great Wall and the cultural heritage. (New Society)