In this paper, a fast 3D reconstruction method based on structured light for the raceway groove of bearings is presented. As to our method, digital parallel grating stripes distributed with sine density are projected onto the raceway groove by a DLP projector, and distorting of stripes is encountered on the raceway groove. Simultaneously, aided by three-step phase-shifting approach, three images covered by different stripes are obtained by a high-resolution CCD camera at the same local location of the raceway groove, thus a more accuracy local topography can be obtained. And the bearing is then rotated on a high precision computer-controlled rotational stage. Three images are also obtained at next preprogrammed location through the trigger of the motor. After one cycle, all images information is combined to get the 3D information in form of a full 360° raceway groove. According to the assemble simulation and running result, the bearing windage can be obtained, especially, the raceway of bearing balls centers can be calculated. Thus, most bearing running parameters can be got before being really assembled. The one of our goals is to simulate the state of bearings with more exacter prototyping during assembling and running. As a result, a simulation based on the obtained 3D topography of the raceway groove is discussed.