Municipal solid waste incineration (MSWI) fly ash has high leaching toxicity of heavy metal and contains dioxins, which is extremely harmful to the environment. It is designated as hazardous waste. Therefore, fly ash must be stabilized before landfill treatment. By introducing the leaching toxicity of heavy metals and the pollution characteristics of dioxins in fly ash, the research progress of the treatment technology of MSWI fly ash was systematically elaborated for the treatment of dioxins and heavy metals. According to the process principle, it is divided into three types of technologies: physical and chemical treatment, thermal treatment, and stabilization and solidification. The high-temperature treatment process was emphasized. Especially, the plasma melting technology can achieve high-efficiency degradation of dioxins, and the solidification effect of heavy metals is great. In addition, the product of the plasma melting technology has high leaching resistance and environmental stability, which makes it show a better performance in the subsequent use of building materials. Therefore, the plasma melting technology is considered as an effective technology for MSWI fly ash treatment with great development potential and industrial application prospects. The current treatment of MSIW fly ash with development potential was summarized, the disposal principle, research status and industrial prospects of each process were analyzed. Finally, the future improvements and development directions for existing problems were suggested.