Loudspeaker structure of noise reduction earphone

The utility model discloses a loudspeaker structure of a noise reduction earphone, which comprises an earphone shell, the end part of the earphone shell is provided with an inner cavity, the end part of the earphone shell is provided with a shell cover, the top of the shell cover is provided with a protective cylinder, the edge of the end part of the earphone shell is provided with an annular groove, and the shell cover is provided with a fixing screw. A voice coil assembly is arranged in the protection cylinder, a silica gel sound nozzle is arranged at the end of the protection cylinder, a sound outlet hole is formed in the silica gel sound nozzle, a passive vibrating diaphragm is arranged on the earphone shell and located in the inner cavity, and a limiting assembly convenient to adjust is arranged on the earphone shell and located on the outer side of the passive vibrating diaphragm. According to the utility model, the passive diaphragm is limited up and down and left and right through the abutting block a