The invention discloses a water control valve. The water control valve comprises a valve body; a first fluid channel, a second fluid channel, a cavity with an outlet, and a piston are arranged in the valve body; the piston communicates with the first fluid channel and the cavity; the piston is pushed by the pressure in the cavity to change the openness in the first fluid channel; the second fluid channel is provided with an inlet and an outlet; the outlet of the second fluid channel communicates with the cavity; and a porous medium is arranged on the inlet of the second fluid channel. The water control valve can control high flow rate of crude oil and low flow rate of water under the same conditions to achieve the purposes of stabilizing oil production and controlling water cut.