The invention belongs to the technical field of concrete buildings, and particularly relates to a test device for reinforced concrete plane structure corrosion, which comprises a transparent enclosure, and four transparent side boards are tightly assembled to form the transparent enclosure; outside the transparent enclosure, a fixing steel cage for fixing the transparent enclosure is mounted along the periphery of the transparent enclosure and the joints between the transparent side boards; a waterproof pad is fixedly stuck to the open end of the bottom of the transparent enclosure, and the waterproof pad is used for being tightly connected to the base of a reinforced concrete plane structure specimen to form a containing body for containing the reinforced concrete plane structure specimen and chloride solution. The structure of the test device is simple, and the test device is easy to operate and convenient to assemble, is safe, reliable and low in cost, can be repetitively used, and can be used for testing the durabilities of corroded reinforced concrete plane structures.