Research conclusions: Pipe pile featured with the high strength， short construction period and easy control of construction quality can meet the high demand of construction of passenger dedicated line with less total settlement and less settlement velocity at the different phases compared with other reinforcement methods． In the soil foundation，under the action of horizontal force，pipe pile is in failure state due to the bending moments． The check calculation of the entire stability of the subgrade is made with the shear strength，resulting in high safety coefficient valuations． The load bearing modes of the pipe pile include the modes of pile － raft structure，pile － board structure and pile － net structure．It is proposed to strengthen control of the construction quality，to improve the strength of soil between piles and the pipe pile＇s top connections and to do the research on pile － beam structure．