The invention discloses a mechanical product collaborative simulation platform system and a simulation method thereof. The mechanical product collaborative simulation platform system comprises a simulation workbench module, an operation flow management module, a simulation data management module, a simulation portal module and a simulation data exchange module. The simulation workbench module comprises a simulation process modeling tool and a simulation flow operating tool and is used for carrying out simulation process modeling and operating control over mechanical products. The operation flow management module comprises an operation flow modeling tool and an operation flow managing tool and is used for carrying out operation flow modeling and operating management on the mechanical products. The simulation data management module is used for uploading, downloading and retrieving simulation data in the simulation process of the mechanical products. The simulation portal module comprises a user management tool, a project management tool and a report management tool and is used for carrying out collaborative simulation platform system configuration, user and permission management, project information management and report generating and checking management on the mechanical products. The simulation data exchange module is used for carrying out data exchange between the collaborative simulation platform of the mechanical products and a PDM system.