Abstract: The resource utilization of metallurgical waste is a difficult and hot issue in the mineral processing industry. The metallurgical silicon slag fiber was used to improve the properties of the mine filling paste,and the basalt fiber and carbon fiber were used as control to discuss the influence of the fiber type and content on the strength of the modified filling paste. Combined with the microscopic test results,the action mechanism of fiber in filling paste systems was analyzed. The results show that the compressive strength of the filling paste increases first and then decreases with the increase of the fiber content. The addition of silica slag fiber has the best reinforcement effect on the filling paste,followed by basalt fiber,and carbon fiber is the worst;The tensile strength enhancement effect is better than the compressive strength;Many cracks appear when the ordinary filling paste is damaged,while the fiber sample doped with silicon slag maintains high integrity when it is damaged;The bridging effect between hydration products and fibers can be effectively inhibited the expansion of the cracks in the specimen, thus enhance the bonding effect of the mortar and promote the improvement of the strength of the filling paste. This study can provide an important reference for the performance improvement of mine filling paste and the utilization of silicon slag fiber resources