To evaluate the safety of thread embedding acupuncture therapy (TEAT) and discuss the prevention and treatment of some adverse events (AEs). Review of databases, including China National Knowledge Infrastructure (CNKI), CBMdisc, Wanfang, VIP databases and English literature published in PubMed, MEDLINE, EMBASE and Web of Science, were searched from their inception to January 2020, randomized controlled trials (RCTs) and case reports in which AEs with TEAT were included. Cochrane Collaboration's tool and RevMan V.5.3.3 software were used to evaluate the quality of the studies. A total of 61 studies (45 RCTs and 16 case reports) with 620 cases of AEs were included in this review. These studies were published in two countries: China and South Korea. Twenty eight kinds of AEs were summarized. The most common AEs were induration, bleeding and ecchymosis, redness and swelling, fever, and pain. They were accounted for 75.35% (425/564) in the review, and most of them were mild. The rarest AEs were epilepsy, irregular menstruation, skin ulcer, thread malabsorption, and fat liquefaction, with 1 case each. But not all of them had clear causal relationship with TEAT. Most of the AEs were local reactions [with incidence of 9.83% (480/4,882)] and systemic reactions accounted for only 1.27% (62/4,882). Although the included studies showed that AEs were very commonly encountered (11.09%), only 5 cases of severe AEs reported from 2013 to 2017 (0.1%) by using catgut thread, which are rarely seen nowdays with the wide use of new absorbable surgical suture. All of the severe AEs were recovered after symptomatic treatment with no sequelae. The evidence showed that TEAT is a relatively safe and convenient therapy especially since application of new absorbable surgical suture. Improving practitioner skills, regulating operations, and paying attention to the patients' conditions may reduce the incidence of AEs and improve safety of TEAT.