The work aims to synthesize a new type of environmentally friendly corrosion inhibitor, and study the corrosion inhibition performance of corrosion inhibitor on Q235 mild steel in 1 mol/L hydrochloric acid solution at 25 ℃. AM (acrylamide), MAA (methacrylic acid), AMPS (2-acrylamide-2-methylpropanesulfonic acid), AMHB (3-(acrylamidomethyl)-2- hydroxybenzamide)) and SMA (octadecyl methacrylate) were heated and stirred to synthesize a new type of hydrophobic association complex containing capsaicin-derived monomer PAMAAS according to a certain ratio. The weight loss experiment, electrochemical method, surface analysis method and theoretical calculation were used to evaluate the corrosion inhibition efficiency of PAMAAS. PAMAAS had excellent corrosion inhibition performance on mild steels. When the mass concentration was 2 g/L, the weight loss inhibition efficiency reached 92.56%. The weight loss experiment results of monomer control showed that the efficiency of polymer was higher than that of the monomer. Electrochemical experiments showed that when the inhibitor mass concentration was 2 g/L, the corrosion inhibition efficiency reached about 92%. According to the analysis of electrochemical impedance spectroscopy test and contact angle test, PAMAAS corrosion inhibitor formeda highly hydrophobic (141.2°) adsorption film on the surface of mild steel. From the scanning electron microscopy and laser confocal microscopy, the surface of mild steel was well protected in the presence of corrosion inhibitors. According to the fit analysis of the adsorption model, it was found that the inhibitor PAMAAS was adsorbed on the surface of mild steel by chemical adsorption-based mixed adsorption, and its adsorption model followed the Langmuir adsorption isotherm, and its fitting regression coefficient reached 0.9999. Quantum chemical calculations of the polymer monomers showed that the corrosion inhibition performance of the polymer was better than that of monomer, which was consistent with the results of weight loss experiments of the monomer control. PAMAAS is a highly effective and environmentally friendly mixed corrosion inhibitor.