The utility model relates to a change high -pressure pump frequency conversion control system between waterwheel, including touch -sensitive screen, PLC controller, high -pressure pump, converter, high -pressure pump ac contactor and circuit breaker, the touch -sensitive screen is connected the PLC controller, the PLC controller is connected the converter, the converter is installed in the major loop of high -pressure pump, high -pressure pump ac contactor connects the circuit breaker, the circuit breaker line of connecting, the power input end U1 of converter, V1, W1 correspond through heat outage ware and connect high -pressure pump ac contactor's drawer is qualified for the next round of competitions, the U2 of converter, V2, W2 be qualified for the next round of competitions and the high -pressure pump motor is connected, the supplementary voltage output terminal of the 24Vvdc of converter with start / parking terminal, slope select the terminal short circuit. The utility model discloses after transforming the starting mode of high -pressure pump as variable frequency starting, its output torque will slowly increase to rated torque, and water pump export water pressure will can not suddenly change, but slowly increases to operating pressure.