Abstract: This article explores the influence of the interactive ratio of limestone powder and fly ash on the performance of paste filling materials. Prepare a series of samples using limestone powder instead of fly ash at 0, 25%, 50%, 75%, and 100% substitution percentages. The working performance and compressive strength of the paste filling body were evaluated by testing indicators such as expansion rate, slump, bleeding rate, setting time, and compressive strength. The research results indicate that the interaction ratio of limestone powder and fly ash has a significant impact on the performance of mineral paste filling materials. As the replacement amount of limestone powder increases, it can effectively reduce the bleeding rate and setting time of the filling material, and improve the expansion rate of the paste. When the replacement amount is around 25%, the compressive strength of the filling material is enhanced. When the curing period is greater than 3 days and the replacement amount of limestone powder is greater than 25%, the compressive strength decreases with the increase of the replacement amount.