Permanent magnet synchronous motors (PMSMs) have the advantages of high power factor, good dynamic characteristics, high safety, and high torque density, and are widely used in ship electric propulsion systems. High-performance control of PMSMs requires rotor position and speed information. Installing mechanical position sensors increases the cost of the drive system, adds control difficulty, and reduces power density. Therefore, research on sensorless control technology for PMSMs is of great practical significance. Proportional-integral (PI) parameters are key factors affecting the dynamic performance of PMSM sensorless control systems. Traditional PI parameter tuning methods include the critical gain method, the decay ratio method, trial and error method, and theoretical calculation method. These methods require specific conditions and are computationally intensive and time-consuming. On the basis of traditional PI parameter tuning, this paper introduces the grey wolf optimization (GWO) algorithm to simulate the PMSM sensorless control system based on the high-frequency injection method, compares the dynamic performance before and after optimization, and verifies the correctness of the theory. This study provides a new approach for PI parameter tuning of PMSM sensorless control using the high-frequency injection method.