In order to obtain uniform white light beam of high luminance, a kind of homogenized beam combination system is designed based on fly-eye lenses, the light sources consist of red, green and blue semiconductor lasers. There are two fly-eye lenses modules in the optical path, the first one is used to generate uniform white light spot, while the second one is used to transform the white light spot into spatially uniform white beam. The optical tracing software is used to simulate the optical path, and the luminance and color uniformity of light distribution at different locations in space are analyzed. The simulation results show that uniform white light beam is obtained, and the feasibility of the optical system is verified theoretically. The experimental facility is set up, and the color spectrometer is used to measure the combined white beam at the distances of 1, 2, 5 m. The test results show that the illumination uniformity is greater than 90%, and color coordinate standard deviation is less than 0.0027. The uniform white light beam combined by this optical path can be widely applied to medical phototherapy, display and automotive lighting, with the advantages of high luminance and uniformity in color coordinates and spatial intensity.