Thiourea base rosin imidazoline quaternary ammonium salt was synthesized,and the structure of thiourea base rosin imidazoline quaternary ammonium salt was characterized by FT-IR and 13C NMR.The static weight-loss method,potentiodynamic polarization test,electrochemical impedance spectroscopy test and contact angle test were conducted to investigate the corrosion performance of target product for A3 carbon steel in the mass fraction of 15% hydrochloric acid solution.The adsorption film of the product was characterized by atomic force microscope test and X-ray electron spectroscopy test.The results showed that the corrosion inhibition efficiency of the product increases first and then decreases with the increase of the mass fraction of the product,and the highest inhibition efficiency reached 90.78% at the product mass fraction is the quality of hydrochloric acid 0.4%;This product acted as the mixed type corrosion inhibitor dominated by cathode;AFM and XPS results show that the target product can form inhibitor adsorption film on the surface of carbon steel.