Objective:To systematically evaluate the efficacy of low dose whole-lung irradiation in COVID-19 pneumonia based on the present evidence.Methods:All literature related to the application of low dose whole-lung irradiation in COVID-19 pneumonia were retrieved from Pubmed, Embase, the Cochrane Library, Web of Science, Google scholar, Scoupus, CNKI, Wanfang database, VIP database until May 2022. Two researchers independently screened the literature. For the literature that met the inclusion criteria, both data extraction and literature quality evaluation were blinded. Revman 5.3 software was used for statistical analysis.Results:A total of 5 controlled clinical trials involving 194 patients met the inclusion criteria. No statistically significant differences were detected in the low dose whole-lung irradiation group compared with the best supportive care group for clinical recovery rates, intubation rates, radiographic improvement rates and 28 d-overall survival.Conclusions:In patients of COVID-19 pneumonia, low dose whole-lung irradiation conferred no significant benefit to clinical outcomes. Currently, the routine use of low dose whole-lung irradiation for the treatment of moderate to severe COVID-19 pneumonia is not recommended.