Through the analysis of movement forms of backfilling slurry in the pipeline self-flowing transportation system and the sedimentation law of backfilling aggregate granule, it is known that the transportation stability of backfilling slurry is related to transportation speed and the length of horizontal pipeline. Combined with the characteristics of gangue paste-like slurry in Suncun Mine, the pipeline transport process of slurry is simulated by Fluent, which is a well-known fluid analysis software, and also the self-flowing transportation feasibility of paste-like slurry with gangue as main backfilling aggregate is researched in theory. The research shows that the self-flowing pressure can overcome the resistance loss in the way of the transmission pipeline. When the horizontal pipe transmission speed is 3.82 m/s, the vertical pulsating velocity component of slurry (Sv) can reach 38.3 cm/s and the interfering sedimentation speed of gangue (Vgg) is just 0.99 cm/s, it can know that Sv > Vgg. Therefore, paste-like slurry can arrive at the mined-area by self-flowing transportation.