Abstract: Because of its own characteristics， the filling mining technology has been vigorously promoted in the mining field， and the determination of reasonable filling slurry ratio scheme and technical parameters of pipeline transportation in filling system is an important prerequisite to ensure the safe， efficient and stable operation of the whole filling system. Taking an iron mine in Tangshan as an example， the filling slurry with a lime-sand ratio of 1∶8 was selected as the test object， the diameters of the test pipeline 140 mm， 160 mm， 180 mm， 200 mm， 220 mm， 240 mm and 260 mm， and 68%， 70%， 72% and 74% of the filling slurry concentration are respectively selected to analyze the factors affecting the resistance loss of the filling slurry pipeline. The results show that the pipeline resistance loss is inversely proportional to the pipe diameter， and the higher the slurry concentration， the greater the pipe resistance loss； When the pipeline diameter increases to 240 mm and 260 mm， the slurry flow velocity at the bottom of the pipeline will be so rapid that the bottom pipeline is easily worn； In order to achieve the balance of mining and filling in the mine production， it is suggested that the pipe diameter of the mine be 200 mm or 220 mm， and the slurry transport concentration be 70%.

Key words: Filling, Pipeline, Resistance loss, Optimization