Automobile gearbox assembling line is a typical dynamic discrete system. It is very difficult to guarantee the layout reasonability and running reliability of the system with traditional experience design. In the paper, with the given automobile gearbox assembling line, visual simulation was adopted to realize the design and management of the system. The methods of queue-service net and event scheduling were applied on the modeling of assembling line and simulation of running process, respectively. And through the experiments on the system, the optimal number of AGV and reasonable scheduling rule were obtained.