In order to improve the early strength of paste filling and explore the microscopic mechanism affecting the early strength of the filling body,ratio experiments were conducted with a certain mine as the engineering back-ground on the technical schemes,that is adding coarse aggregate gravel and adopting an independently developed new cementitious material,respectively.The test results showed that the scheme of adding coarse aggregate gravel could meet the technical requirements of 28 d strength ≥5 MPa under most working conditions.However,to meet the requirement of 3 d strength≥2.5 MPa,it is necessary to add more than 40 % coarse aggregate gravel,and ensure a concentration of more than 74 % and a cement-sand ratio of 1∶4 or more.On the other hand,the technical scheme using the new cementitious material as a binder could generally meet the technical requirements of 3 d strength ≥2.5 MPa and 28 d strength ≥5 MPa with a concentration of 72 % or above.Scanning electron microscopy (SEM )analysis of the test blocks using the new cementitious material revealed that it promoted the development of calcium aluminate crystals inside the filling body,thereby significantly enhancing the early strength.The conclusions and relevant technical parameters of the experiments can provide technical support for future filling system construction in the mine.