The gas pipeline of the second gas production plant of some Company is made of Q345R steel. The corrosion behavior and process of Q345R steel in wastewater samples and wellhead produced water samples were studied by short-term immersion experiment, laser confocal microscopy, Raman spectroscopy and electrochemical experiments. The results showed that the carbon steel Q345R was corroded to a certain extent in the comprehensive wastewater and imported produced water samples, and there was local pitting corrosion. The corrosion rate in the produced water sample is higher. This is because the lower pH and higher concentration of chloride ions in the wellhead produced water accelerate the corrosion of Q345R carbon steel. Combined with relatively high concentration of IOB in wastewater, IOB can rapidly oxidize Fe2+, promote the conversion of γ-Fe2O3 to α-Fe2O3, and form a dense α-Fe2O3 film on the surface of the sample to protect the matrix. In addition, under the action of suspension of solution and corrosion products on the surface of the sample, the migration of ions in the water is prevented and the corrosion of the sample is slowed down. Through the comparison and mechanism study of the corrosion behavior of Q345R steel caused by the comprehensive wastewater of wellhead produced water, the suggestions on the Anti-corrosion direction of the treatment pipeline and equipment of produced water in the gas field are put forward.