As to the problem that the assembly cycle and costs of quayside container crane always exceeds 40% of the entire production cycle and costs, improving the assembly efficiency becomes an important link to enhance the competence of port machinery manufacturing enterprises. In the product assembling cycle, virtual assembly can help to improve assembly quality and reduce the cost. Based on the physical structure of 45t quayside container crane, 3D components model were developed, the assembly hierarchy and modeling process were provided. The simulation analysis of assembly sequence was taken based on the CATIA DMU platform and virtual assembly animation was generated. The assembly interference detection results were analyzed to verify the part assembling ability, the whole disassembly and assembly process was displayed, which can help the assembly workers making visual analysis of fitting operation rationality.