A method for chamfering the installation position of a water control valve of a faucet body, mainly using a punching machine to drive a processing punch to punch a first end or second end, where the processing punch is provided with a fillet corresponding to the hole of the first end or second end, which squeezes the burrs through the driving of the punching machine, allowing the surface of installation position of the water control valve to be even and smooth, achieving smooth rotation of the water control valve, and preventing the water stop rubber to be scratched by the burrs or sharp corners.