Aiming at the problems of complex scene objects, lack of correlation between them, close coupling between modelling knowledge and modelling process, and low flexibility of scene configuration in dam safety monitoring scene construction, this paper proposes a multi-level semantic constraint method for dam safety monitoring scene construction. First, based on the analysis of the characteristics of dam safety monitoring scene modelling operations and modelling knowledge expression, modelling knowledge is extracted from spatial pose semantic constraints, spatial layout semantic constraints and component combination semantic constraints, and modelling knowledge and modelling operations are stored in a parametric way. Then, after the multi-level semantic constraint rules constrain and guide the way the scenario objects are combined, the dam safety monitoring scenario is generated. A prototype dam safety monitoring system is developed based on this approach to validate the effectiveness of the method.