Due to the ambiguity between different safety status levels in the safety assessment of crane operations and the randomness of data acquisition, a crane safety assessment scheme based on a cloud model and improved combined weighting is proposed. Taking the currently in-service quayside container crane (hereinafter referred to as the quayside crane) as the object, the cloud model is introduced to evaluate the metal structure of the quayside crane. The attribute values of each assessment index are quantitatively analyzed to determine the membership degree of each structure to each safety level. The DEMATEL and improved CRITIC methods are combined with the multiplication combination weighting to calculate the combined weight of the indicators, determine the comprehensive membership degree of the cloud model, and judge the safety level of the crane. This is then compared with the assessment results obtained by traditional methods. The results show that the method's results are consistent with actual engineering practice, verifying the effectiveness and feasibility of the method, and it can more objectively reflect the true operating state of the crane.