The invention provides a closed-loop test method for a rotating speed control system of an electric water feeding pump. The closed-loop test method comprises the steps that a test device simulates aninitial start signal, a starting mode signal and a rotating speed set value signal of the electric water feeding pump, and correspondingly generates control signals capable of being directly input; the test device receives a scoop tube position set value signal of the rotating speed control system of the electric water feeding pump and conducts PID simulation operation on the scoop tube position set value signal to obtain a position signal value of a scoop tube position sensor after simulation operation, a simulation operation value is compared with a scoop tube actual position signal value obtained after the rotating speed control system of the electric water feeding pump conducts executing according to the control signals, and if a comparison result is within the preset error range, it is output that the performance of the rotating speed control system of the electric water feeding pump is qualified; and if the comparison result is not within the preset error range, it is output thatthe performance of the rotating speed control system of the electric water feeding pump is not qualified. By implementing the closed-loop test method, closed-loop test is conducted on the rotating speed control system of the electric water feeding pump, the problem that repeated test operation on field equipment is inconvenient can be relieved, the human operation error risk is lowered.