A machine tool cooling system and cooling method which allow cost reduction by reducing the number of control valves, and in which opening/closing control is simple are disclosed. The machine tool cooling system and cooling method include a hot oil tank storing hot oil, a cold oil tank storing cold oil, a first to third hot oil passages and a first to third cold oil passages, which supply the hot oil and the cold oil to a first to third heat generating portions, a hot oil return passage returning the hot oil to the hot oil tank, a first to third supply control valves interposed in the first to third cold oil passages, and a valve controller controlling opening/closing of the first to third supply control valves so that the cold oil is supplied to the first to third heat generating portions intermittently at different timings.