The reporter learned from the Yunnan Observatory on the 5th that Dr. Li Zhenwei and his collaborators of the large sample stellar evolution research group of the observatory have successfully constructed the double white dwarf star family in the Milky Way galaxy using the newly obtained stability criterion of mass exchange and the evolution model of the binary star family. The research results were published in the famous international journal Astronomy and Astrophysics. White dwarf is an ancient fossil in the universe. Double white dwarfs are a binary system composed of two white dwarfs rotating around each other, and their combination can produce type Ia supernovae as the standard candle of cosmology. Some close and double white dwarfs have orbital periods of only a few minutes, and are important target sources for future space gravitational wave detectors. In the process of formation of binary white dwarfs, they must undergo at least one binary material exchange, and the stability of material transfer directly determines the final evolution of binary stars. By establishing the adiabatic material loss model (Ge model), the researchers have given the criteria for the stability of mass transfer of stars in different evolution states. Compared with the results given by the multi-party model in the early research, the new criterion believes that the transfer of biomass from stars to giant stars tends to be more dynamic and stable. Based on this, researchers have successfully constructed the double white dwarf star family in the Milky Way. The theoretical calculation shows that the Ge model can better reproduce the observed distribution of the merging rate of double white dwarfs and the distribution of the merging rate of double stars containing extremely low mass white dwarfs, and can better solve the contradiction between the spatial density of double white dwarfs in the early theoretical model and the observation. On this basis, Li Zhenwei and others further studied the influence of the merging of the two white dwarfs on the type Ia supernovae and the gravitational wave radiation properties of the two white dwarfs, providing theoretical support for the corresponding observations. (Outlook New Era)