Fabricated lengthened screw-in round steel pipe concrete pile

The utility model relates to an assembly type screw-in round steel pipe concrete pile capable of being lengthened, which comprises a foundation pile, a lengthened pile, an inner joint, a pile head and a loading connector, a screw-in spiral piece is arranged on the outer surface of the circumference of the foundation pile, the foundation pile and the lengthened pile are in threaded connection through the inner joint arranged between the foundation pile and the lengthened pile, the lengthened pile is in threaded connection with the pile head, and the pile head is fixedly connected with the loading connector. The prefabricated steel plate is prefabricated, transported to the site and mechanically installed, and the cast-in-place procedure is omitted, so that pollution to the environment is reduced. The field operation amount is small, templates are saved, the construction period is greatly shortened, the labor cost is saved, and the manufacturing conditions are improved. The lengthening requirement of the concre