Abstract: The inter-regional hydropower project is characterized as large engineering quantity, complex environment and prone to risk and accident. To overcome the deficiencies of the current risk-assessment methods in hydropower projects such as randomness, fuzziness and subjectivity of evaluation body, we propose the improved multilevel fuzzy comprehensive evaluation model on the basis of cloud model to assess the risk of the inter-regional hydropower projects. We analyzed the risk factors systematically and established the multilevel fuzzy evaluation index system, which was improved by the cloud model. The corresponding cloud models of remark set, risk factor weight, membership degree and comprehensive evaluation results are constructed. The established method was used to assess the risk of the flood discharging projects on both banks of a hydropower station, and the assessing result has some applicability and practical meanings