Abstract: In view of the complex broken ore-body at the underground metal mine with characteristics of difficultly and poor safety，much waste-rock，long filling pipe and complex construction of surface filling plant etc..The mobile backfilling system is researched successfully in the underground mine by improving equipments of concrete mixer and concrete pump，which applies mobile filling pump and pumps waste-rock filling material with high-pressure and high-concentration to stope，and this system is applied in NO.2 western sandstone ore with compound and broken of Hunan Baoshan Mine.Practice proves that this backfilling system has the merits of moving nimbly，high-pressure pumping，high concentration，high efficiency，low cost，and simple pipe installation，etc.It realizes treating waste-rock on-site and mining safety in underground mine.

Key words: Underground mine, Complex orebody, Mobile type, High-pressure pumping, Back-filling system