Objective To evaluate the effect of post mastectomy radiation therapy (PMRT) on breast reconstruction after mastectomy in breast cancer patients, in order to provide evidence support for clinical treatment decisions.Methods Five databases searched in the current study include the Cochrane Library, PubMed, CNKI, VIP and WanFang database. A systematic search for control trials was performed in each database from the starting date of each database to March 1, 2021. After the two evaluators independently selected literature, extracted data and conducted quality evaluation according to the inclusion and exclusion criteria, the meta analysis was carried out by Revman 5.3 software.Results A total of 9 controlled studies (3 447 cases) were included, including 699 cases in radiotherapy group and 2 748 cases in non radiotherapy group. The results of meta-analysis showed that: PMRT was associated with significant increase in capsular contracture. The incidence of capsular contracture increased from 4.34% in the no radiotherapy group to 34.10% in patients receiving PMRT ［RR=9.25, 95%CI (3.76, 22.78), P<0.000 01］ . In addition, PMRT was associated with a significant increase in reconstructive failure ［RR=2.55, 95%CI (1.74, 3.74), P<0.000 01］ and revisional surgery ［RR=2.24, 95%CI (1.58, 3.18), P<0.000 01］. Moreover it was associated with a significant reduction in patient satisfaction ［RR=0.29, 95%CI (0.15, 0.57), P=0.000 3 ］ and cosmetic outcome ［RR=0.26, 95%CI (0.15, 0.43), P<0.000 01 ］.Conclusion This meta-analysis demonstrates that within the first two years post breast reconstruction for those patients who receive PMRT, the rates of adverse events is increased and there is significant reduction in patient satisfaction and cosmetic outcome.