The invention discloses a radiation cooling system for temperature control of electronic equipment close to space vehicle, comprising an electronic equipment pressure maintaining cabin, a liquid storage tank, a pump, an in-cabin finned-pipe heat exchanger, a fan for an in-cabin radiator, a radiation cooling surface, a pipeline, a diverter valve and circulating fluid working medium, the inlet of the pump is connected with the outlet of the liquid storage tank, the inlet of the liquid storage tank is connected with the outlet of the in-cabin finned-pipe heat exchanger, the inlet of the extravehicular radiation surface is connected with one outlet of the diverter valve, and the circulating fluid working medium is filled in the pipeline; in the invention, a fluid loop coupling type radiation cooler is arranged according to the space environment of the stratosphere and the thermal loading condition of the fluid loop, waste heat in the electronic equipment is transmitted to the extravehicular radiation cooling surface through the fluid loop and is discharged to the ambient atmosphere under the radiation cooling function; the radiation cooling system is used in special working environment at bottom part of a stratosphere to carry out heat radiation of high-power electronic equipment, and the structure is compact.