Abstract: In recent years, with the need of acting on international convention and the development of the enterprises themselves, EPC contract mode gets a wide range of applications. Compared with the traditional contracting mode, contractors take most of risk in EPC projects. It is more important for the contractors to make risk assessment in EPC project. Among some risk assessment methods, such as AHP and fuzzy evaluation method, the data is based on expert review. The results are of subjectivity. In this study a new method and procedure was put forward, in which the data is based on the study of similar or related cases and optimized. This method made the quantitative analysis of risk assessment more accurate and objective. The model was tested by example using 5 case studies with good results. The example showed that this method of quantitative analysis was effective in EPC contract projects risk assessment for contractors, which provided a basis for contractors to make decision.