The invention relates to a construction method of a steel pipe pile bailey truss foundation full-space support system. The construction method comprises the following construction steps of 1) construction preparation; 2) erection of a steel pipe pile guide construction platform; 3) installation of a pile cap of a steel pipe pile sinking pile; 4) guide driving of a steel pipe pile; 5) extension construction of the steel pipe pile; 6) arrangement and positioning of a profile steel bottom beam; 7) arrangement of bailey beams; 8) arrangement of distribution beams; 9) laying of a platform plate; and 10) counter-force prepressing of the platform. The construction method has the beneficial effects that a construction trestle is used as a support body of a support longitudinal beam, a support cross beam is arranged on a cantilever section of the support longitudinal beam, the position of a guide groove pipe is limited through the support longitudinal beam and the support cross beam, the erection difficulty of the steel pipe pile guide construction platform is reduced, and the structural stability is improved; and a sliding hoop and a sliding control plate are arranged on the outer side wall of the steel pipe pile, the sliding control plate is connected with a position control groove plate, and the transverse position of the steel pipe pile can be limited through the position control groove plate.