In order to compare the collimation effect of TIR (Total Internal Reflection) lens and free-form reflector for LED (Light-Emitting Diode) light source. Based on TracePro, the effective range and spot diameter of LED light source are simulated under TIR lens and reflector of the same caliber, and the collimation characteristics of TIR lens and reflector of the same caliber are compared. The results show that with the increase of aperture, the range increases, and the light pattern goes through three stages, and the corresponding light spot has three forms, namely rectangular shape, double peak shape and hump shape. After the light source passes through the reflector, the spot diameter is smaller and there is lag effect. The range of LED light source after passing through the TIR lens is longer, but the difference is small. When the aperture of the spot is too large, both optical systems form rings.