本发明公开了一种后注浆钢管桩及注浆方法，该后注浆钢管桩包括钢管桩、注浆管和排气管，钢管桩径向设置有多个隔板，相邻两个隔板之间形成注浆封闭空间，注浆管沿钢管桩的桩壁内侧轴向通长设置，在若干个注浆封闭空间内设置有出浆口，用于向注浆封闭空间内注浆，排气管沿钢管桩的桩壁内侧轴向通长设置，在若干个注浆封闭空间内设置有排气口，用于在向注浆封闭空间内注浆时，注浆封闭空间向外排气。本发明通过向钢管桩的桩身内设置的多个注浆封闭空间注浆，形成多段实体桩身，在提高钢管桩整体刚度的同时，能够根据施工土体工况选择实体桩身的段数，降低注浆成本，解决了目前钢管桩抗弯刚度不高、施工难度大、用材浪费的技术问题。

The post-grouting steel pipe pile comprises a steel pipe pile body, a grouting pipe and an exhaust pipe, a plurality of partition plates are arranged on the steel pipe pile body in the radial direction, a grouting closed space is formed between every two adjacent partition plates, and the grouting pipe is arranged in the axial direction of the inner side of the pile wall of the steel pipe pile body in a full-length mode; grout outlets are formed in the multiple grouting closed spaces and used for grouting the grouting closed spaces, the exhaust pipes are arranged in the axial direction of the inner side of the pile wall of the steel pipe pile in a full-length mode, and exhaust ports are formed in the multiple grouting closed spaces and used for exhausting air outwards in the grouting closed spaces when grouting is conducted in the grouting closed spaces. The multiple grouting closed spaces arranged in the pile body of the steel pipe pile are grouted to form multiple sections of solid pile bodies, the number of the sections of the solid pile bodies can be selected according to the working condition of a construction soil body while the overall rigidity of the steel pipe pile is improved, the grouting cost is reduced, and the construction efficiency is improved. The technical problems that an existing steel pipe pile is not high in flexural rigidity, large in construction difficulty and waste in used materials are solved.