The invention discloses a control system of a direct current power transmission converter valve pure water cooling device. The control system comprises a power system and a control subsystem, wherein the power system comprises a master circulating pump, a water replenishing pump, electric heaters, a fan and a double-power switching device; the main circulating pump is electrified through a soft start device; the fan is electrified through a double-power switching system; the electric heaters are divided into two groups which are connected with two paths of alternating current power sources through breakers respectively; the water replenishing pump is connected with the two paths of alternating current power sources through the double-power switching device; and the control subsystem is used for controlling the main circulating pump, the water replenishing pump, the electric heaters and the fan. According to the control system of the direct current power transmission converter valve pure water cooling device provided by the invention, the electric heaters of which one is used and the other one stands by, an electric butterfly valve and an air supply electromagnetic valve are separately electrified by the two paths of alternating current power sources respectively, so that the situation that all the equipment are powered off and cannot logically and normally operate when the double-power switching device fails can be effectively prevented.