In order to obtain gemini imidazoline quaternary ammonium salt corrosion inhibitor with good inhibition performance，three gemini imidazoline inhibitors of quaternary ammonium salts，including metronidazole G1，asymmetric imidazoline G2 and bis-imidazoline G3，were synthesized by using epichlorohydrin，thiourea and three different amines. Chemical soaking for weight loss，electrochemical polarization curves and electrochemical impedance spectroscopy （EIS） were applied to compare the inhibition behaviors of three inhibitors on X52 steel in produced water of a certain natural gas well with 34330 mg/L salinity. The effect of inhibitor concentration on the inhibition efficiency was studied，and the mechanism of gemini quaternary ammonium salt corrosion inhibitor was analyzed. The results showed that inhibitor G1 and G2 were asymmetrical，while inhibitor G3 were symmetrical. Three inhibitors exhibited excellent inhibition performance. The corrosion rate of X52 steel decreased significantly and the corrosion inhibition efficiency increased with increasing concentration of three inhibitors at 76℃ . Three inhibitors were arranged according to the corrosion ability in following order：G3>G2>G1. All the adsorption and inhibition of three inhibitors on the surface of sheet steel accorded the Langmuir adsorption isotherm. The adsorption mode obeyed mixed-type of synergized chemisorption and physisorption. The three gemini quaternary ammonium salt corrosion inhibitors were all mixed corrosion inhibitors with anodic inhibition as the main factor. The film forming effect on the surface of X52 steel had a great influence on the electric double layers. Due to the difference of molecular structure and symmetry of three corrosion inhibitors，the coverage of X52 steel surface during adsorption process was affected，resulting in the difference of film forming behavior and corrosion inhibition performance of three inhibitors.