A control valve for a faucet includes a valve housing, a hollow valve seat, two sealing gaskets, at least one water outlet channel, a rotation plate, a control unit, two mounting seats, a fixed sleeve, and a movable sleeve. Thus, the movable sleeve is movable in the fixed sleeve to control the water flow rate of the mixed cold and hot water to the optimum value to regulate and stabilize the water pressure automatically so as to provide a pressure balance effect so that the mixed water flowing from the water outlet channel is kept at a constant temperature, thereby providing a comfortable sensation to a user.