In order to improve the starting performance of high-power marine diesel engine, a steady state model of marine diesel engine is established with GT-power software, an air motor starting system module is added, and a transient model of starting process of diesel engine is constructed. Based on the simulation results, the influence law of environmental exhaust back pressure, lubricating oil temperature, and compressed air system parameters on the starting performance of diesel engine is analyzed. The simulation results can provide basis for the system parameter design and performance evaluation of high-power marine diesel engine based on the air motor starting.