Pile bottom grouting for bored pile means grouting cement slurry into the sediment and surrounding soil mass to largely increase their strength by fully filling the soil pore of the sediment at the pile tip and the soil mass to a certain range. By the physical and chemical effect, the strength was greatly enhanced to increase the vertical bearing capacity of single pile. Based on the construction practice of pile bottom grouting for bored pile of high speed railway, the paper introduced two kinds of grouting process and elucidated the importance of improving working efficiency, ensuring grouting quality and the implementation of key technical measures.