A foldable expandable umbrella-shaped antenna structure skeleton and its unfolding method, the structure skeleton consists of a base, a primary rod, a rotating shaft, a secondary rod, a torsion spring, a retaining piece, a spring, a drawstring, a connecting rod, a nut, and a lead screw Composition; the circumference of the base is connected to the bottom end of the first-stage rod through a rotating shaft; the top end of the first-stage rod is connected to the bottom end of the second-stage rod through a torsion spring hinge; the clamping part-spring-drawing rope-rotating shaft constitutes a clamping structure, and the second-stage rod is folded The curved top is clamped in the clamping structure; the lower part of the primary rod is connected with the nut in the circumferential direction through the connecting rod, and the nut is installed on the lead screw to form a lead screw nut structure; the lead screw drives the nut to move upward, and the structural skeleton is retracted; the lead screw drives the nut to Move down, the structural skeleton is opened, the rotating shaft rotates through a certain angle, pull the pull cord to open the clamping structure to release the constraint, and the torsion spring drives the secondary rod to open; in this way, the structural skeleton is unfolded; the umbrella-shaped antenna structural skeleton of the present invention has a small folded size , large size, repeated retractable, light structure, high reliability.