The invention discloses a variable-frequency adjustable-speed variable-pressure water supply control method. The variable-frequency adjustable-speed variable-pressure water supply control method adopts a water inlet pipeline connected with a low-position pool and a water supply pipeline connected with a user pipe network, parallelly-connected water pumps are arranged between the water inlet pipeline and the water supply pipeline and are respectively connected with a frequency converter, and a remote water meter and a pressure transmitter are arranged between a pump set outlet and the water supply pipeline. The pressure transmitter, the remote water meter and the frequency converter are all connected with PLC control cabinet. The pressure transmitter acquires a pressure measurement value of the pump set outlet. A set pressure value is calculated according to the flow acquired by the remote water meter. The frequency of the frequency converter or start and stop of the water pumps are adjusted according to the size relation of the two parts. The variable-frequency adjustable-speed variable-pressure water supply control method belongs to a broken-line variable-pressure variable-frequency water supply system and is simple in structure, simple in control line, low in initial investment and safer in water supply. In addition, a pump set water supply curve is closer to a pipe network characteristic curve, and the energy-saving advantage can be further played.