A wavelength conversion element includes a base plate and a rotating device. The base plate has a first surface and a second surface. The first surface is configured to allow a fluorescent layer to dispose on. The base plate includes some first grooves and some second grooves. The first grooves are disposed on the first surface around a center of the base plate. The second grooves are disposed on the second surface around the center. The first grooves and the second grooves are staggered from each other along a rotating direction. The base plate has some through holes. Each of the through holes communicates with the second surface and the corresponding first groove. The rotating device is connected with the base plate and configured to drive the base plate to rotate about an axis along the rotating direction. The axis passes through the center.