A detection device adapted to detect lens surface and a stitching interferometer including the same are disclosed. The detection device includes: a cylindrical detection frame comprising support bosses arranged on an inner wall of the detection frame in a circumferential direction of the detection frame, the lens to be detected being placed on the support bosses; and a plurality of support units mounted at a bottom of the detection frame in the circumferential direction of the detection frame, each of the support units comprising: a support mechanism configured to be movable in an axial direction of the detection frame and cooperate with the support bosses so as to support the lens to be detected together; and a balance mechanism configured to provide a balancing force for balancing with force of the support mechanism for supporting the lens to be detected, so that axial support force of each supporting unit for the lens to be detected is equal to axial support force of each support boss for the lens to be detected in both cases where the axial direction of the detection frame is parallel to a gravity direction of the lens to be detected and inclined with respect to the gravity direction of the lens to be detected.