Due to the high risk of construction sites, it is necessary to make safety risk evaluation. With the synthetic consideration of the complexity and uncertainty of construction sites, a comprehensive evaluation index system with two levels has been based on the emphases and difficulties of the current safety work in construction industry; the index system includes civilized construction site, management of machinery, equipment, materials, occupation health protection, and the subpackage management, such as 6 one-level evaluation indexes, inspection system of safety risk, safety awareness education, and prevention and control of occupation disease, such as 33 two-level evaluation indexes. The research takes “No. A residential building and other 8 projects” as the empirical analysis object, with the weights of the first indexes and second indexes being calculated by the analytic hierarchy process (AHP) and the information entropy, and applies the unascertained measure to comprehensively evaluate the safety risk of the construction project. The overall score of the project is 6.4475, the evaluation result is good, which is consistent with the actual situation, and the feasibility and effectiveness of the evaluation index system and evaluation model are verified, which provides a reference for safety risk management in the construction stage of construction projects.