The utility model relates to an elastic-pressing frame mechanism of air-tightness detection equipment for a shell. The adopted technical scheme is as follows: the elastic-pressing frame mechanism comprises a mounting base, a bearing plate, guide blocks, a pressure lever and a baffle; the cross section of the guide block is in an L shape, the guide blocks which are arranged systematically are fixed at left and right sides of the bottom of the mounting base, the bearing plate is arranged between two guide blocks and is pressed by the guide blocks, and a cushion block is arranged between the bearing plate and the mounting base; and the rear side of the bearing plate is limited by the baffle on the mounting base, and the front side of the bearing plate is limited by a gasket at the front end of the guide block, and the pressure lever for pressing a sealing workpiece shell is arranged at the bottom of the bearing plate. In the utility model, the structure is smart and reasonable, the pressing reliability is high, the pressing force can be adjusted flexibly, a balance pressure lever is arranged, the rigidity and the stability of the elastic-pressing frame mechanism are improved, and the sealing points can be ensured to be sealed reliably.