The invention provides a base member of a 5G signal support tower. The base member of the 5G signal support tower includes slidable outer cylinder and inner cylinder which nest each other, a double-head motor is fixedly arranged on the inner wall of the outer cylinder, a second output shaft of the double-head motor is coaxially and fixedly provided with a second screw rod, the second screw rod extends to the opening of the bottom end of the outer cylinder, the second screw rod sleeve a lifting block capable of sliding in the length direction of the outer cylinder in a threaded connection mode,mounting openings are formed in the four peripheral surfaces of the lifting block, rectangular bottom plates capable of being extended downward from the opening of the bottom end of the outer cylinder are further arranged in the outer cylinder, the four bottom plates are in one-to-one correspondence with the mounting openings, a rotating shaft formed by the positions where the bottom plates and the lifting block are rotatably connected are axially parallel to the width directions of the bottom plates, the bottom plates are arranged to be in interchangeable hidden state and open state, in thehidden state, the bottom plates are located in the outer cylinder and are located between the mounting openings and the opening of the bottom end of the outer cylinder, and in the open state, the bottom plates protrude outward from the opening of the bottom end of the outer cylinder and is perpendicular to the outer cylinder.