Based on PLC controller and the heating principle of IGBT, using the regulated voltage signal generated by PLC output module to input LM3524 and to produce PWM pulse signal, and then passing PC929 isolation and the pushpull amplifier of the triode to drive the IGBT, a new type of high density simulated heat source was designed. To maintain a constant heat power output, the PLC was used to control the water spray system, and the PID was used to adjust the duty ratio of PWM signal to control the onoff of the IGBT, and the closed loop control of calorific value with IGBT was constituted. The real time monitoring to the whole system working state was realized by RS485 communication. Experimental results show that the designed heat source power control system has better response speed and working stability, the designed spray system achieves expected cooling effect and the heating power can reached to 125 W. The designed heat source can be used for evaluating spray cooling effect and the performance of heatemission of the IGBT component in hydraulic control valve and actuator, and it is of good application prospect.