Abstract: This invention provides a moving iron unit for loudspeakers, which includes coil, iron core, diaphragm, and magnet, among which, the iron core is disposed in the coil, and the magnet is connected to the diaphragm on a transmission basis. It is characterized in that it also includes vibrating ring, to which the magnet is secured, and which is secured to the inner wall of a shielded cavity through its elastic body disposed radially, and which is connected to the diaphragm on a transmission basis through the transmission rod. Further, the unit comprises two diaphragms, which are disposed symmetrically at two sides of the vibrating ring and connected respectively to the vibrating ring on a transmission basis through a transmission rod. The coil is shaped directly by coiling on the iron core.