The utility model provides a five-degree-of-freedom lens adjusting device which comprises a three-dimensional adjusting mechanism, a lens clamping seat and a rotating device, wherein the rotating device comprises a first rotating device and a second rotating device; the first rotating device comprises a first rotating support plate, a first rotating shaft, a first upper adjusting screw and a first lower adjusting screw; the second rotating device comprises a second rotating support plate, a second rotating adjusting plate, a second rotating shaft, a second upper adjusting screw and a second lower adjusting screw; a plane where the second rotating support plate is located is in parallel to a plane where the second rotating adjusting plate is located; the second rotating support plate and the second rotating adjusting plate are arranged on two sides of the lens clamping seat; and a plane where the second rotating support plate is located and a plane where the first rotating support plate is located are perpendicular to each other. The five-degree-of-freedom lens adjusting device can accurately adjust the perpendicularity of the lens and has the characteristics of simple structure, convenient adjustment, economization and practicability.