Slurry is a necessary material in high-speed railway pile foundation construction. A lot of waste slurry which is harmful to the eco-environment will be generated after the construction is finished. If the slurry isn’t disposed properly, it will cause serious pollutions to the environment. This paper analyses environmental impact of waste slurry through four aspects: surface water, crops, soil and wastewater treatment system etc. Finally, it gets the conclusion that there are four methods to reduce the environmental pollutions of waste slurry: the first one is using the environment-friendly slurry in pile foundation construction; the second one is raising the slurry use efficiency; the third one is decreasing the amount of slurry usage and the output of waste slurry; the last one is developing the more eco-friendly waste slurry treatment methods.