Abstract: During the process of development, there are always exist carbon dioxide, hydrogen sulfide and other corrosive gases in oil and gas reservoirs, severely affecting the normal production in oil and gas fields. Testing wire to conduct a field trial, the corrosion characteristics of well steel wires are analyzed based on the spectrum analysis, the electron microscope scanning, and the metallographic analysis. Results show that corrosion laws and characteristics vary a lot in different well depth. The corrosion products and appearance as well as the corrosion rate are not the same. The electrochemistry corrosion intensifies as the temperature and pressure increase. Pitting corrosion dominates the well head corrosion, while stress corrosion dominates the downhole corrosion. The experiment results can be a good reference for corrosion prevention of oil and gas wells.