Abstract: In this paper, the control technology of outlet temperature of cooling water chiller in mine is introduced. In mine explosion-proof refrigeration device, traditional manual three-position four-way valve is replaced through the flameproof type solenoid valve, and flameproof type solenoid valve switch is controlled through the program control; temperature at the outlet of the mine water chilling unit can achieve automatic adjustment, which not only improves the mine refrigeration system operation efficiency, but also improves the reliability and stability of the system with good application effect.