The present application provides a projection device. The projection device of the present application includes a lens barrel and a thermal transfer assembly disposed on an outer wall of the lens barrel; the thermal transfer assembly includes a first thermal transfer structure and a second thermal transfer structure, the first thermal transfer structure is disposed on the outer wall of the lens barrel and extends along an axial direction of the lens barrel, one end of the second thermal transfer structure is disposed at one end of the first thermal transfer structure, and the other end of the second thermal transfer structure extends away from the axial direction of the lens barrel. The application can effectively dissipate thermal when the lens assembly is working.