Since the 1980s, microwave ovens have entered the homes of ordinary people. Using microwave ovens to cook or reheat food is convenient and fast, and has become an indispensable tool in daily diet. However, with the improvement of people's health awareness, many people are worried about whether the microwave will leak and affect the nutrition in the food when they use the microwave oven to cook and heat food? As long as the electrical appliances are not damaged, microwave leakage will not occur. Microwave is an electromagnetic radiation similar to radio waves and infrared rays. Microwave ovens use microwave to cook, thaw and heat food efficiently. As far as microwave oven products are concerned, microwave leakage prevention technology and production process of products can limit microwave leakage to less than 10 W/m2. For qualified microwave oven products, microwave leakage will not occur if they are not damaged in use. There is not enough evidence to prove that microwave cooking can induce cancer. In 2013, the results released by the Chinese Academy of Home Appliances at the research results conference of "The impact of microwave cooking on food safety and nutrition" sponsored by the Chinese Academy of Home Appliances showed that, under the premise of reasonable cooking, as long as the temperature and heating time are controlled, the changes in the molecular structure of food are harmless. There is not enough evidence to support the opinion that microwave cooking may increase carcinogens in food or cause adverse mutagenesis. In the study of biological effects of microwave, there is no research result and evidence that microwave can induce gene mutation in animals and plants. The loss of vitamins and chlorophyll in microwave ovens for vegetables and fruits is relatively small. The Chinese Academy of Home Appliances, together with national food professional testing institutions, compared the nutritional components of foods cooked with microwave and open fire, including vitamins, fats, proteins, minerals, etc. The results show that microwave cooking will not cause the loss of nutrients faster and more serious than traditional cooking. At the same time, in terms of protection of vitamins, minerals and other nutrients that are sensitive to heating time, the effect of microwave heating is obviously stronger than that of open fire heating. Studies have proved that when vegetables, fruits and other foods are cooked with microwave, the loss of vitamin C, flavonoids and chlorophyll is small when they reach the same central temperature due to short heating time. The loss of water-soluble vitamins, such as vitamin C and vitamin B, is related to the amount of water added in the cooking method. Microwave cooking can better retain water-soluble vitamins in food because it does not need to add water or only adds a small amount of water. It is not recommended to cook n-3 unsaturated fatty acid food in microwave oven, specifically including: some fish, meat, egg yolk and other food containing n-3 unsaturated fatty acid, as well as yogurt and other food containing live bacteria will be affected by microwave, and the nutritional components will be damaged, so heating in microwave oven is not recommended. Any form of cooking and processing methods, including heating and cooling, will change the physical properties, chemical composition and nutritional characteristics of food. Therefore, it is necessary to reasonably and scientifically select the cooking method of food, and absorb more nutrition in food while satisfying the color, smell and taste. Some suggestions for using the microwave oven should be kept in mind. 1. Carefully read the user manual, use the microwave oven scientifically and reasonably, and select the heating time and microwave power reasonably. It should not be too long or too strong. 2. Cooking