The purpose of this study was to evaluate the efficacy and safety of Tanreqing capsule in the treatment of mild and common COVID-19. The trial was a randomized, double-blind, placebo-controlled, multicenter clinical trial design. A total of 480 patients were divided into 2 groups: experimental group and control group 3:1. Patients in both groups received basic treatment with vitamin C effervescent tablets. Tanreqing capsule was added to basic treatment in the experimental group, and placebo was added to basic treatment in the control group. The treatment course was 7 days, and the observation period was set to 7 days, with a daily visit.