Fabricated building simulation system based on BIM

The invention relates to an assembly type building simulation system based on BIM, and the system collects the size of an assembly type component before construction, calculates the theoretical and actual size errors of the assembly type component, and carries out the distribution characteristic determination of the errors. An active error conforming to the error distribution is generated based on the distribution characteristics of the error, and then a three-dimensional model of the fabricated component is modified based on the active error. And obtaining a three-dimensional model containing an actual error. Then assembling is conducted, the stress of all the assembly type components in the assembly type building is analyzed through a stress analysis tool, and second stress data is obtained; and meanwhile, first stress data without errors are generated. Stress data in two modes are provided and are visually displayed to management personnel. Therefore, the building stress data based on the actual error is p