Abstract: To solve the problem that the simulation research results are not credible by lacking the procedure of model verification for the assembly line, the model's verification process is twice introduced based on the summary of the current simulation research, and a complete simulation procedure for the assembly line proposed. To verify the effectiveness of the procedure, taking the actual assembly line as an example, the impact of logistics line layout, the number of bottleneck machines, AGV's quantity and AGV's speed on production capacity are considered based on the analysis of layout and process flow, and 24 schemes are designed and constructed based on Plant Simulation software. After all the simulation models are verified, the best scheme is obtained by comparing the productivity and the utilization rate of the machine. The simulation result shows that the optimized capacity is increased by 227% compared with the original plan, the bottleneck machine utilization rate increased by 51%, and the average machine utilization rate by 121%. It is concluded that the proposed simulation optimization procedure is feasible and effective, which can provide guidance for the simulation research and application of the assembly line, and has reference significance for the simulation research in other production fields.