Abstract: In view of heat dissipation existed in the high-power LED light, an optimization design was applied to the radiator of the high-power LED with a shroud under the air-cooling condition. A fluid analysis software was used to optimize the internal diameter and height of the shroud, the diameter of the inlet and the angle of the heat sink-s fins while the parameters of the fin structure were fixed. By changing these parameters, the parameters of the gas on the surface of the heat sink were changed in fluid shape and wind speed, and finally the convective heat transfer coefficient of the fin was changed. Through optimizing, a series of optimum parameters belonging to the shroud and the heat sink were obtained: the shroud-s height was 85mm, the inlet diameter was 76 mm, the outlet diameter was 83 mm and the angle of the heat sink was 9.It is concluded that the temperature of the heat sink has a certain degree of reduction after optimization, which can provide an optimized scheme for the cooling design of high-power LED lamps.