Double elbow dieclosing mechanism is an important part of hot chamber diecasting machine，which determines the quality and productivity of die casting. In order to improve the rationality of the design of double elbow dieclosing mechanism and meet the requirements of various working conditions, the structure compactness of the dieclosing mechanism was improved to increase production efficiency and reduce production cost. In order to avoid the complicated problems caused by the multiobjective optimization on the original physical prototype, the opening and closing processes of dieclosing mechanism were analyzed by multibody dynamic analysis and optimization software ADAMS_View, and the displacement and velocity curves of the moving templace and the cross were obtained. Furthermore, the sensitive values of parmeters to the optimization objective were optimized. The results show that the speed of moving template for double elbow dieclosing mechanism optimized by software ADAMS is higher than that before optimization, so as to improve productivity of die. Under the condition of satisfying the requirements of various working conditions, the weight of double elbow dieclosing mechanism is reduced, and the manufacturing cost is lower