The current greenhouse effect and the "dual-carbon" goal have set off a new wave of refrigerant substitution, requiring new refrigerants to achieve a comprehensive balance between environmental protection, safety and thermal properties. However, there are currently no ideal substitutes for these refrigerants. Most environmentally friendly refrigerants, such as R290, R32, and R1234yf, which have low ozone depletion potential (ODP) and Global Warming Potential (GWP), are flammable and pose safety risks. Identifying suitable flame retardants for environmentally friendly flammable refrigerants has emerged as a crucial focus of current research on refrigerant alternatives. This article provides a recent overview of research progress on the compatibility of flame retardants with flammable refrigerants. The main focus was categorizing the various flame retardants and assessing their efficacy across different flammable substances. It also discusses their performance, effects, mechanisms, and environmental impacts. Furthermore, the article analyzes their potential applications and development trends and recommends flame retardants compatible with flammable substances.