Under the background of urbanization and the improvement of living standard, building energy consumption is increasing day by day and energy saving and consumption reduction in construction industry is imminent. As a new type of energy-saving healthy and livable building, passive building will inevitably become the development trend of future buildings. Based on the factors that affect the energy consumption of passive buildings in hot summer and cold winter areas, this paper finds out the main influencing indexes, calculates the accurate index weight by AHP and corrects it by entropy weight method in order to be more objective. Finally, the method is applied to an example and relevant suggestions are put forward based on the research results and the examples.