The invention relates to the technical field of indoor sanitary pipelines, and discloses a pipeline dredging agent auxiliary reaction device which comprises a pipe body. A supporting block is fixedlymounted in the pipe body, a main disc is fixedly connected to the supporting block through a rotating shaft in a clamped manner, a sliding groove is formed in the eccentric position of the main disc,and a connecting pin is slidably connected to the interior of the sliding groove in a clamped manner. The outer wall of the lower end of the connecting pin is rotationally connected with an eccentricdisc in a sleeved manner. According to the pipeline dredging agent auxiliary reaction device, through the arrangement of a base disc, an action disc, a clamping groove, a triangular plate, a water discharging groove, a lower clamping block, limiting grooves and an upper clamping block, a dredging agent is blocked, so that the contact time of the dredging agent and an obstacle is long enough, and the pipeline is easy to dredge; and through the arrangement of the supporting block, the rotating shaft, the main disc, the sliding groove, the connecting pin, the eccentric disc and a bearing interlayer, large obstacles generated after dredging are crushed, secondary blockage of the pipeline is prevented, the pipeline dredging effect is good, and the pipeline dredging efficiency is high.