With the widespread application of new technologies and new equipment, due to the differences between ship power systems and land power systems, it is necessary to model and digitally simulate the ship electric propulsion system. This paper establishes a mathematical model of the ship’s electric propulsion system, and uses Matlab to initially implement digital simulation of the system. The simulation adopts a hierarchical structure and modular design. Based on the slip frequency speed regulation control strategy, the motor speed, electromagnetic torque, three-phase current and dq-axis current of the asynchronous motor starting process and loading process are simulated and analyzed. Under two common working conditions, the speed change curve was simulated and verified using the slip frequency speed regulation control strategy and without using the control strategy. The examples proved the correctness of the simulation model and method.