The invention relates to a radiating device for a computer chip and a working method of the radiating device. The radiating device comprises a radiating tank, a water cooling device and water cooling pipes, wherein the water cooling device comprises heat sinks, a shell, a water inlet and a water outlet; the radiating tank comprises an outlet, an inlet and a fan groove, and a fan is arranged in the fan groove; the outlet and the inlet are communicated with the water inlet and the water outlet respectively through the water cooling pipes; the heat sinks are specifically aluminum-material sheets adopting U-shaped opposite structures. The radiating device has the advantages that radiating area is increased favorably, a radiating effect is increased, maintenance cost is lowered, and service life is prolonged.