The deep foundation pit project of urban subway station is affected by complex engineering geology and hydrology, many surrounding buildings and underground pipelines, and narrow construction work surface. There are many uncertain factors in the construction process, and the risks should not be underestimated. Therefore, a risk assessment model is established for subway deep foundation pit construction based on the C-OWA operator-two-dimensional cloud model. Through literature research and actual investigation, conduct risk analysis from both the main body of the foundation pit and the surrounding environment is made, and a risk index system is established for subway deep foundation pit construction, using the C-OWA model for weighting, and combine the weighted integration method of the cloud model to construct a comprehensive evaluation Cloud digital features and two-dimensional cloud images. Case analysis shows that the risk evaluation results of subway deep foundation pit construction are critical risks, which are consistent with the actual situation, and provide theoretical references for project managers.