The present invention discloses a speaker module and an assembling method of the speaker module and relates to the technical field of electroacoustic products. The structure of the housing of the module is improved in the present invention, so that first performing the ultrasonic welding between the shells, then mounting the speaker monomer into the inner cavity of the module and at last sealing the front acoustic cavity by coating the glue are realized, which effectively solves the disadvantages caused by first mounting the speaker monomer and then performing ultrasonic welding in prior art. According to the present invention, in the course of the assembling, the occurrence of the problems of the damage of the speaker monomer, the deformation or breaking of the shells and the leakage of the front and the rear acoustic cavity is avoided, and the end products of the speaker modules of the present invention have a high qualified rate.