Building on the connotation of the public perceived efficacy， this paper constructed an evaluation index system for the public perceived efficacy of online drug purchase，specifically including six first-level indicators of safety，effectiveness，economy，accessibility，convenience and satisfaction degree，and 22 subordinate second-level indicators. Based on this system，an empirical study on the public perceived efficacy of online drug purchase was conducted using the structural equation model. The results showed that the public perceived efficacy of online drug purchase was generally close to good，and the public perceived safety and effectiveness were relatively high. However，there remained a gap between the price of online drug purchase and the public expectation， and the overall public satisfaction of the online drug purchase was poor. Accordingly，it is necessary to promote aspects such as medical insurance payment，improve service quality， strengthen smart regulation，and enhance drug price monitoring and management to improve the public perceived efficacy.