Taking the fly ash of CFB boiler of coal gangue power plant as the research object, through physical and chemical activation, the fly ash was activated, and a series of fly ash-based mineral cementing materials were developed, which are widely used in underground roadway grouting, grouting, underground filling and mining projects. The results show that the green closed-circuit circulation mode of comprehensive utilization of coal gangue, electricity and fly ash was realized by innocuous treatment of fly ash and turning waste into treasure.