The solid volumetric true−3D display requires light source with high brightness, high energy utilization rate and high frequency color field. So high−power red, green and blue LEDs with collimators were used as the projection light source. Firstly, the required quantity of LEDs was determined according to the required output luminance, the efficiency of the projector and the red, green and blue LEDs' parameters. Secondly, with the consideration of the LEDs' dimensions, light−emitting mode and output luminous flux, collimator was designed and simulation model was established. Simulation and practical measurement results both show that light source based on high−power LED meet the requirements of the solid volumetric true−3D display.