The application of LED in illumination is generalized.LED array with multiple circles with three-dimensions,based on the photometric principle and the luminous characteristic of LED,is modeled in CAD software,A spherical surface with the characteristic of uniform illumination as a light source is achieved,and the model of the reflection with the figure of revolving cone is obtained,which is imposed to TracePro to execute ray tracing to get the chaa of illuminance conforming to the standard of illumination.The structure of designing is simple to save the time of design and the cost of manufacture.