A coolant control valve unit for a vehicle is disclosed. The coolant control valve unit includes a cam having an upper surface to which a driving axle is connected and a lower surface having at least one sloped surface with a profile set in a rotation direction on the basis of the driving axle, a valve provided in a rod supported on one side of the sloped surface, an actuator rotating the driving axle to push the rod along the profile of the sloped surface of the cam to cause the valve to open and close a coolant passage, a cam cover supporting an upper surface of the cam, and an annular cam bearing interposed between the cam cover and the cam, excluding a central region in which the driving axle is formed.