Using the extending non-imaging optics theory and based on the principle of equalization of the distribution ratio of the luminous flux of incident rays to reflective ones in certain area of the surface，the direc-tion of the corresponding reflective ray to each incident ray is ascertained.Then the shape of reflector can be at-tained easily.According to the emission characteristics of light，area，irradiance and uniformity to design the re-flector，then TracePro can be used to simulate the design.The results show that using this method to design the reflector can reduce the time and improve the efficiency.And the design can meet the requirements well.