Abstract: By using polycarboxylate superplasticizer, naphthalene water reducing agents and melamine water reducing agents, this paper analyzes the influence of different water reducing agents and additions on the slump and expansion of the filler slurry through experiments, and combines the measured slump value with the Murate model theory to calculate the yield stress of the slurry.The results show that when 0.05% polycarboxylate superplasticizer is added, the yield stress of the slurry will be reduced from close to 400 Pa to less than 60 Pa, which is beneficial to pipeline transportation, if the polycarboxylate superplasticizer is continuously increased to 0.2%, the slurry begins to segregate.For the slurry with naphthalene water reducing agents, when the additive amount is 0.5%, the yield stress of slurry is less than 60 Pa, and the fluidity reaches the optimal level, continuous addition of naphthalene water reducing agents has a negative impact on the strength of filling body.For filling slurry with melamine water reducing agents, the optimal addition amount of water reducing agents is 0.5%, if it is less than 0.5%, which can not meet the requirements of self-flow transport, if it is more than 0.5%, which will affect the formation of high-quality slurry.Based on the comprehensive analysis of the yield stress and economic cost, the use effect of polycarboxylate superplasticizer is better than that of naphthalene water reducing agents and melamine water reducing agents, which is more conducive to improving the flow of slurry.