The invention provides an optical module test circuit, a test device and a coding test system and belongs to the optical module test filed. The test device comprises a test base, a clamp, a connection module, a test circuit, a push module and a buckle press module. The test base is provided with a switch and a groove; the clamp is provided with a positioning groove; the connection module is fixedly connected with the clamp; the push module is used for pushing an optical module in the positioning groove and fixing the optical module in the test base; the buckle press module is used for pressing a buckle of a sheet metal cover of the optical module positioned in the test base; the connection module is used for connecting the optical module and the test circuit; and the test circuit is connected with the buckle press module and the push module. The beneficial effects are that the functions of automatic positioning and fixation of the optical module, automatic ground-housing short-circuit test, automatic coding and automatic sheet metal cover buckle pressing are realized; the production process is simplified; and loss due to long turnover time among processes is reduced.