The functions and structure of a virtual operation training system for tower cranes was described, and virtual scene modeling techniques of the system was investigated in this paper. The virtual scene model of building site and environment around a tower crane were set up based on Creator softward. Model optimization techniques were used to reduce the number of model surfaces and model nodes, which saved system resources and improved system running speed. Model driver was realized in VC++ by calling Vega functions, which achieved the performance of real-time interaction between trainers and the scene. The techniques provide the foundation for developing the virtual real software of virtual operating system for training operators.