This article introduces the simulation analysis of an automobile enterprise engine cylinder block machining line.Based on the plant simulation, the capacity of the production line, the utilization rate of the gantry manipulator, the number of the zero point clamping and the number of the dummy head are analyzed.According to the result of the simulation, the capacity of the production line is evaluated, the design scheme of the production line is diagnosed and the optimization measures are put forward, those provide the de- cision reference for the production line designing and show the application prospect of the modeling and simulation technology.