Abstract: Addressing the issues of long transmission chains, low efficiency, high maintenance costs, and oil leakage in the gear drive system of cooling tower fans, research was conducted on the electromagnetic design and optimization of a direct-drive permanent magnet synchronous motor for 110 kW/157 RPM cooling towers. The operating mechanism was clarified, and the structural parameters of the motor were determined. A two-dimensional simulation model was established based on the finite element method, and electromagnetic characteristic analysis was completed under no-load and rated load conditions. An improved rotor magnetic circuit scheme was proposed, and the performance indicators of the motor before and after optimization were compared. The research results showed that after optimization, the cogging torque of the motor decreased by 86.39%, the rated load torque fluctuation decreased from 6.75% to 3.57%, and the rated output torque increased from 6.683 kN·m to 6.703 kN·m, significantly improving the operational smoothness of the motor. This provides theoretical basis and technical support for the engineering design of similar low-speed high-torque permanent magnet motors.