Abstract: Aiming at the characteristics of rail transit construction risk, the sinusoidal fuzzy number comprehensive evaluation model was embedded in the cloud model, and the risk assessment method of cloud model based on sinusoidal fuzzy number was constructed. Firstly, the sinusoidal fuzzy number model was established to determine the risk index weight.And then, it was transformed into a cloud model through reverse cloud computing. The overall risk level of whole project was obtained through the basic principles of cloud computing. Finally, this method was applied to evaluate the construction risk level of the section from Baoshun road station to Huashan road station of Wuhu rail transit line 1. The results show that the performance of sinusoidal fuzzy number is more practical, and the cloud model can transform the fuzziness of risk factors in construction between qualitative and quantitative. The proposed evaluation method is rigorous and the evaluation results are reasonable.