A compressing diaphragm pump with multiple effects includes an eccentric roundel mount with three cylindrical eccentric roundels, a pump head body with three operating holes, and a diaphragm membrane with three annular positioning protrusions. A basic curved groove or other positioning structure is circumferentially disposed around each operating hole while a basic curved protrusion or other mating positioning structure is provided in the diaphragm membrane for suitably coupling with the corresponding groove or positioning structure in the pump head body upon assembly, resulting in a shortened length of moment arm from the basic curved protrusions or other positioning structures and an annular positioning protrusion, and a reduction in vibration-caused noise and resonant shaking in comparison with a conventional compressing diaphragm pump. The cylindrical eccentric roundels each includes a sloped top ring extending between an annular positioning groove and a vertical or inverted frustoconical flank of the eccentric roundel mount resulting in an extended service lifespan of the compressing diaphragm pump.