Abstract:The traditional construction of China's construction industry faces the problems of high pollution, high cost and low efficiency, while the assembly technology can alleviate the difficulties faced by the traditional construction. China has a large land area, and there are great differences in assembly development among provinces. Through analyzing related policies of assembly development, a 5-dimension evaluation index system was constructed. DEMATEL method, AHP method and TOPSIS evaluation method were used to evaluate and analyze the development level of prefabricated buildings in five provinces and cities in southwest China. The results show that there are significant differences in the development of prefabricated buildings in southwest China, among which Sichuan province has the best development of prefabricated buildings, while Yunnan Province lags behind other provinces and cities and is relatively weak.