Abstract: This is an essay in the field of mining engineering. High-value utilization of rare earths in fly ash can effectively alleviate the environmental pollution caused by fly ash in my country, expand the supply chain of rare earth raw materials, and ensure the strategic safety of rare earths. This article summarizes the research on rare earth element extraction technology reported from fly ash in recent years, and introduces the research progress of acid method, acid-base combined extraction technology and precipitation method and extraction method. The advantages and disadvantages of the three rare earth element extraction and separation processes are compared. It is pointed out that the research on the extraction technology of rare earth from fly ash can be based on the process flowsheet of the existing industrial equipment for extracting aluminum oxide and gallium from fly ash. The exploration of the collaborative extraction and development of aluminum, gallium and rare earth from fly ash can not only speed up the development of the extraction of rare earth from fly ash. The industrialization of the extraction and application of rare earths in coal ash also can further realize the comprehensive utilization of fly ash and increase the added value of fly ash.