The invention discloses a transmission device of a passive optical network. The device comprises a mounting box, a base, a sliding rod, a socket, transmission equipment, a plug, a pressing plate, bolts and a nut seat. The mounting box is a square box body, and the base is fixedly connected to the two sides of the interior of the mounting box. Sliding grooves are formed in the rear part of the base, and the two ends of the sliding rod are connected into the sliding grooves of the base in a sliding mode. The socket is fixedly connected to the sliding rod, and the transmission equipment is inserted into the mounting box. The plug is fixedly connected to the tail part of the transmission equipment, and the plug and the socket are in one-to-one correspondence. The pressing plate is fixedly connected to the front end of the transmission equipment, and through holes are formed in the two sides of the pressing plate. The nut seat is fixedly connected to the front end of the base, and the boltspenetrate through the through holes of the pressing plate and are connected with the nut seat through threads. A parameter adjusting panel is arranged on the upper end face of the transmission equipment, and a spring seat is arranged on the inner side of the interior of the mounting box. The device has the advantages of simple structure, convenience in operation, good use effect and the like.