Abstract the PWM control technology has been one of frequency conversion technology core technologies. From uses the analogous circuit to complete the triangle modulating wave and the reference sine wave comparison at first, produces the sine pulse-duration modulation SPWM signal to control the power component's switch start, uses the entire digitized plan to at present, completes optimized the real-time online PWM signal output, may say until present, PWM still occupied the dominant position in each kind of application situation, and has been the hot spot which the people study. SIMULINK unified the diagram contact surface and the interactive simulation ability misalignment dynamic system simulation tool. It take the MATLAB core mathematics, the graph and the language as the foundation. Realizes using SIMULINK to the PWM profile simulation may obtain the PWM standard wave pattern, the profile analysis and teacher the teaching has the important use regarding PWM. key words: PWM; Pulse-duration modulation; Simulation; SIMULINK; Matlab