The invention discloses a pressing device applicable to assembly of polypropylene filter elements. The pressing device comprises an operating table, a top plate, a first air cylinder, a pressing plate, a second air cylinder, a bearing plate and a limiting plate, and is characterized in that the operating table is arranged on a bracket; the top plate is arranged on upright posts; the first air cylinder is arranged on the top plate; the pressing plate is arranged on a first piston rod; the second air cylinder is arranged at the bottom of the operating table; a second piston rod is arranged on the bearing plate; bearing grooves are formed in the bearing plate; and the limiting plate is arranged on the bearing plate through springs. According to the pressing device applicable to the assembly of the polypropylene filter elements, fastening plates are arranged in the bearing groves through the springs; the fastening plates are arranged in an arc-shaped structure; the fastening plates are pushed through the elasticity of the springs, so that the fastening plates extrude one end of polypropylene filter element skeletons which are placed in the bearing grooves, and the stability of the polypropylene filter element skeletons in the bearing grooves is improved; and therefore, the assembling quality of the polypropylene filter element skeletons and the polypropylene filter elements are improved.