By referring to the existing research results in the field of construction safety of prefabricated buildings, the assessment dimensions and weights are established for the qualitative indicators, which provide the basis for the quantification of qualitative indicators. Based on the investigation reports of recent safety accidents in China and experts' opinions, the safety degree of qualitative indicators can be divided into five grades: Most significant, significant, generally significant, insignificant, and least significant. The evaluation score interval is divided into [(100,80), (80,60), (60,40), (40,20), and (20,0]. The quantitative evaluation index is based on relevant industrial laws and regulations and the relevant production standard requirements, combined with the current development status of China's construction industry. The evaluation index that does not satisfy the requirements is evaluated using the subtraction method with a full score of 100 points and deduction until the end.