A design method of LED uniform luminous intensity lens based on virtual target surface was proposed. Hemispherical virtual target surface was set to establish the energy relationship between chip and target surface, and get the shape of uniform luminous intensity lens. By optical simulation to discuss the influence of radius of virtual target surface to luminous intensity distribution, combining with uniformity of luminous intensity platform and ratio of luminous intensity platform width were proposed to describe lens overall uniformity index. A reasonable radius of virtual target surface was ultimately determined to get a uniform luminous intensity lens that meets the design indexes. Simulation and analysis show that the larger radius of virtual target surface, the smaller calculation error and higher luminous intensity uniformity of lens when the thickness of the lens and angle of lens design goal are constant, the larger angle of lens design goal, the higher luminous intensity uniformity of lens when the thickness of the lens and the radius of virtual target surface are reasonable. Using this method, a half-angle 60 degrees lens of uniform luminous intensity was designed. Its overall uniform luminous intensity is better, and uniformity of luminous intensity platform is 0.983 and ratio of luminous intensity platform width is 0.859, which meets the design requirement.