A speaker module and a manufacturing method thereof is provided in present invention. The speaker module includes a frame, a magnetic circuit system and a vibration system. The vibration system has a vibrating diaphragm and a voice coil. The magnetic circuit system includes a magnet and an upper magnetic plate arranged on the magnet. The speaker module further includes flexible circuit boards electrically connected with the voice coil. The upper magnetic plate and the flexible circuit boards are integrally injection molded in the frame. By virtue of the configuration described in the present invention, the connection between the frame and the magnetic circuit system is precise and stable.