The effective components of the water-soluble corrosion inhibitor 9H contained cationic imidazoline often separate out after long-term injection， which results in that the sea pipe is blocked in high temperature condition or the following processing. In this paper， oleic acid， divinyl three amine and xylene， as raw materials， were used to synthesize oleic acid imidazoline， which was be used in accordance with the requirements of anti-corrosion of pipelines in offshore exploitation. The imidazoline inhibitor was further modified by adding different ratio of epoxy ethane and epoxy propane. Dynamic weight loss method， SEM， EDS and optical profiler was applied to evaluation the inhibition efficiency of the inhibitor， the surface morphology and the influence of inhibitor on film-forming were also analyzed. The optimum inhibitor HS-006 was composed of 5% thiourea and imidazoline which was synthesized by oleic acid imidazoline， epoxy ethane and epoxy propane （mass ratio was 1∶0.1∶0.05） . The inhibition efficiency of the corrosion inhibitor HS-006 to X65 steel sheet could reach 95.03% in the corrosion environment with H₂ S concentration of 50 mg/L under CO₂ partial pressure of 0.4 MPa and the total pressureof 1.0 MPa at the temperature of 95℃， which was higher than that of the inhibitor 9H. The corrosion inhibitor HS-006 mainly inhibit the corrosion caused by cathode reaction and the HS-006 could form a excellent protect film on the surface of the steel sheet