Objective To investigate the synergistic inhibition effects of HPCS, Tw-20 and sodium dodecyl benzene sulfonate (SDBS) on the corrosion of Q235 steel in 1 mol/ L HCl solution. Methods The corrosion experiments of Q235 steel specimens im- mersed in 1 mol/ L HCl solution were carried out. Using static weight loss method, polarization techniques and electrochemical im- pedance spectroscopy (EIS), the inhibition performance of HPCS and its composites were analyzed. Results HPCS had a low inhi- bition efficiency when acted alone at a relatively low concentration, and it reached the highest inhibition efficiency of only 63. 03% when it acted alone with a concentration of 100 mg/ L. The inhibition efficiency of HPCS and Tw-20 increased to 90. 75% with a concentration ratio of 50 mg/ L : 0. 2 mg/ L, while the inhibition efficiency was only 51. 73% when HPCS acted alone with a con- centration of 50 mg/ L. The inhibition efficiency of HPCS/ Tw-20 / SDBS reached 93. 77% with a concentration ratio of 50 mg/ L : 0. 2 mg / L : 20 mg / L, with the advantages of both non-ionic surfactant and anionic surfactant, it could maintain a relatively high inhibition efficiency of 71. 11% at 60 ℃ . Conclusion Tw-20 and SDBS had a strong synergistic effect on corrosion inhibition with HPCS. And the compound inhibitors, HPCS / Tw-20 and HPCS / Tw-20 / SDBS, were both mixed-type corrosion inhibitors, the in- hibitor mechanism of which was coverage effect