Aiming at the problems of coal mining under constructions, difficulty in handling ground gangue of YiQiao Coal Mine, through theoretical analysis, scheme comparison, equipment selection and other methods, the scheme of non-lifting after intelligent separation of underground gangue is proposed, the underground gangue filling mining technology is studied, and the appropriate separating and filling equipment is selected. The cement, fly ash, water and gangue which proportioning 1:1:2.57:20 is confirmed as the dense cementitious filling material, the strength of the filling body is greater than 2.98MPa, the production capacity of the filling working face is 13000t/a, a whole set theories of underground gangue non-lifting through separating and filling system is formed, the engineering application shows that the system satisfies the requirements of coal mining under construction, liberates the amount of coal resources under construction, ensures the effective capacity of the shaft lifting system, digests the mine gangue, and realizes the requirements of green mining in YiQiao Coal Mines.