Abstract: A uniform projection system with a single LED as light source was designed for the purpose of the uniform illumination in a designated region. An optical system with refraction and total internal reflection (TIR) was proposed according to the luminous characteristic of LED and the law of energy conservation. The ordinary differential equations satisfying the spots on the contour curve of TIR refractive and reflective planes were established. The coordinates of points on profile curves were obtained by solving these ordinary differential equations using Runge-Kutta method. The profile curves were acquired by curve fitting of the coordinate spots with software UG, and then TIR model of the projector and data of the surface shape suitable for NC manufacture were obtained. The TIR model of the projector was introduced into Tracepro, and rays were traced. The results show that the illumination uniformity of the illuminated region is better than 92.6%, and the efficiency of the whole system is more than 91.8%.