The utility model discloses a test piece device for a metal corrosion loss rate test of electric transmission line equipment in an atmospheric environment. The test piece device is applied to the metal corrosion loss rate test of the electric transmission line equipment in the Gobi desert environment and comprises a fixed frame (1), a cylindrical test piece (2), an O-shaped test piece (3), a cuboid test piece (4) and nylon ropes (5). With the adoption of the fixed frame structure design, the fixed frame can be firmly fixed on a pole tower of a test point, firmly fixes various test pieces, does not influence sandstorm erosion and natural corrosion of the atmospheric environment and cannot swing with the wind; the nylon ropes have poor water absorption performance, so that measuring errors caused by corrosion increase of mounting holes of various test pieces due to the nylon ropes are avoided; and further, the superficial area of each test piece for the test meets the national standard specification, the material and the shape of each test piece for the test are similar to those of the electric transmission line equipment, and metal corrosion and loss conditions of various types of equipment can be really reflected.