The invention discloses a square wave drive type permanent-magnet brushless DC motor simulation system. The motor simulation system comprises three main parts: a main controller, a motor model simulation link, and a Hall signal generation circuit. The system is built mainly based on a motor electromechanical equation. A three-phase voltage control signal is input from outside, the motor model simulation link simulates the electromagnetic process inside a motor, the main controller simulates the output of state variables of the motor, and the characteristics of a square wave drive type permanent-magnet brushless DC motor are presented. With the system, the load characteristics of a brushless DC motor can be simulated accurately by modifying and debugging the parameters of the motor flexibly. The system plays a very important role both in development and design of a brushless DC motor structure and in design and debugging of a motor driver.