An apparatus for cooling intake air temperature of a vehicle may include a vortex tube receiving high pressure air discharged from an intercooler of a vehicle and then separating the high pressure air using centrifugation into high temperature air and low temperature air; a first bypass line connecting the vortex tube with a compressor, allowing the low temperature air to move therethrough, and selectively opened/closed by a first check valve; a second bypass line connecting the vortex tube with an exhaust line of the vehicle and allowing the high temperature air to move therethrough as a second check valve is opened/closed; and a controller controlling to open or close the first and second check valves.