A radiation module capable of resisting reverse flow of hot fluid includes a fan, a radiator and a retaining tool. The fan provides an inlet and an outlet. The radiator is connected to the outlet of the fan. The retaining tool secures the radiator to a heat generation part. At least a baffle is provided in the radiation module. The fluid enters the fan via the inlet and flows toward the radiator via the outlet to cool the heat-generating component and the hot fluid moving outward the radiator is resisted entering the inlet with the baffle part so as to enhance heat dissipation efficiency.