Abstract: To realize high heat flux dissipation for spacecrafts operating in the harsh space environment and in different working modes, a well-designed thermal control system using the capillary separate spray cooling loop (CSSCL) based on the PID and fuzzy incremental control strategy with a mechanical pump is presented. A 4-node thermal network mathematical representation is established by the node network method and is implemented by the numerical simulation method to analyze the temperature dynamic performance of the thermal control system. The result shows that the CSSCL thermal control system based on the fuzzy incremental control strategy with the pump can achieve a precise thermal control of the controlled object with a faster response and a smaller overshoot than the PID control, which can be used for the development of future spacecraft with the need of high heat flux dissipation of space electronics.