〔Abstract〕 Objective The purpose of this study was to look into the inhibitory effect of ChangShengJieDu decoction on SARS– CoV–2. ChangShengJieDu decoction is a traditional Chinese medicine formula made up of natural herbs and food extracts that have been shown to support justice and detoxification, but it is unclear whether it can inhibit the replication of SARS–CoV–2. Methods Vero cell line was established, and toxicity test and QPCR detection were performed with different dilutions of ChangShengJieDu decoction. Results ChangShengJieDu decoction had almost no toxicity to Vero cells at dilution higher than 1:16; ChangShengJieDu decoction could inhibit the proliferation of SARS–CoV–2 in vitro, and the dilution of ChangShengJieDu decoction that inhibited 50% of SARS–CoV–2 copies was 1:45.024. When the dilution was 1:32, ChangShengJieDu decoction had the lowest cytotoxicity and the best inhibition of wild SARS–CoV–2. Conclusion ChangShengJieDu decoction has certain inhibitory effect on SARS–CoV–2, and has low toxicity to Vero cells.