The invention provides a stable pumping system of a long distance high pressure slurry pipeline. The stable pumping system of the long distance high pressure slurry pipeline comprises at least one main pump, each main pump comprises a crank shaft, drive connecting rods and pistons. The pistons are connected to the drive connecting rods, the drive connecting rods are connected to the crank shaft, rotation of the crank shaft is transformed to suction and discharge motion of the pistons through the drive connecting rods, each main pump comprises two or more two pistons, each piston is connected to the crank shaft through one drive connecting rod, and equal phase difference angles are formed sequentially among all the pistons contained in each main pump. According to the stable pumping system of the long distance high pressure slurry pipeline, the pistons of each main pump in the pump station are at different phase angles, and all the pistons cannot reach the maximum discharge state or the maximum suction state at the same time, so that pressure fluctuation at outlets of the main pumps caused by piston suction and discharge is smooth, the problem of pressure fluctuation in an existing long distance slurry pipeline pumping system is solved, and slurry pipeline conveyance safety is guaranteed.