An integrated cooling system for a fuel cell vehicle according to this invention comprises a fuel gas flow field for supplying fuel gas to a fuel cell stack and exhausting the fuel gas from the fuel cell stack through a fuel gas accumulator, and an air flow field for supplying air to a fuel cell stack and exhausting the air from the fuel cell stack through an air accumulator, wherein at least one cooling pipe of the cooling system comprises a plurality of heat-dissipation pins on a circumferential surface thereof.