Wavelength conversion device and projection device

A wavelength conversion device includes a driver, a substrate, a wavelength conversion layer and a supporting piece. The supporting piece is arranged between the driver and the base plate, and the supporting piece is connected with the base plate and connected to the driver. The driver is used for driving the supporting piece and the substrate to rotate around the central shaft. The substrate has a front surface and a rear surface opposite to each other, the supporting piece is connected to the rear surface, and the wavelength conversion layer is disposed on the front surface. The distance between the outer edge of the supporting piece and the central axis is at least one time the distance between the outer edge of the wavelength conversion layer and the central axis. The wavelength conversion device provided by the invention is beneficial to reducing heat transfer to the driver and is beneficial to improving heat dissipation efficiency. The invention further provides a projection device which comprises a lig