The present invention relates to a corrosion-fatigue-coupled test method and device for a steel bridge deck. The method includes: 1) installing an orthotropic steel bridge deck (OSBD) and pasting filter paper; 2) installing a sodium chloride solution delivery pipe; 3) installing an infrared (IR) lamp; 4) preparing a corrosive solution; 5) coupling corrosion and fatigue; and 6) acquiring test data. A device constructed by using the method includes a to-be-tested OSBD, a support device, a pressure pump, a water tank, a monitoring device, an IR lamp, a plastic water pipe, a thermostat and a rotary sprayer. The present invention solves the problem of laboratory accelerated corrosion of the OSBD. The present invention fully considers a coupling effect of a corrosive medium and an alternating stress, so that the created simulation environment is close to a service environment of the OSBD, and the test data are effective and reliable.