An optical module includes a housing including an optical interface, a circuit board module disposed in the housing, a fiber optic receptacle module disposed in the housing and including a plurality of fiber optic receptacles, an optoelectronic chip disposed in the housing and electrically connected to the circuit board module, a position limiting card disposed behind the fiber optic receptacle module, and a plurality of through holes arranged at the optical interface. The plurality of fiber optic receptacles are installed at the optical interface and fit through the plurality of through holes, and the position limiting card is fixed to the housing and locks the fiber optic receptacle module tightly against the optical interface.