The invention relates to a high-precision free-form surface lens based on a light-emitting diode light distribution curve. The high-precision free-form surface lens comprises a light-emitting diode and a plurality of double-free-form surface lenses with different radiuses; the double-free-form surface lenses are cut into rectangular lens and can form rectangular light spots and are spliced into alens array by using a rectangular lens; the matrix backlight surface is 10 mm x 13. 4 mm, the matrix is a 2 x 2 matrix, the size of the single rectangular lens is 5.05 mm x 6.7mm. Compared with a traditional backlight structure adopting a two-layer diffusion film, the light energy utilization rate of the backlight after the lens array and the two layers of diffusion films are adopted is improved,the backlight brightness is improved and the heterogeneity is improved, the half-brightness visual angle is reduced from 37 degrees to 19 degrees; the lens and the array provided are used for collimating light rays emitted by the LED light sources, so that a uniform rectangular light spot with high brightness is easily formed, and the use requirement of the head is met.