The supporting seat discloses a supporting seat being adjustable in height, which is used for adjusting the line shape and the height of the structure in the building operation process. The supporting seat comprises a left slide rod, a right side rod, a center slide rod, a lower slide rod, an upper slide rod and two sets of regulating devices. The left slide rod, the right side rod, and the center slide rod have the same shape and size, and the longitudinal cross-sections thereof are respectively trapezoids; the top ends of the trapezoids are opposite; the upper slide rod and the lower slide rod are respectively adaptive with the left slide rod, the right side rod, and the center slide rod; the two sets of regulating devices are symmetrically arranged on the front surface and the back surface of the left slide rod, the right side rod, and the center slide rod and respectively comprises a screw shell, a left guide screw and a right guide screw which are respectively arranged on the twoends of the screw shell in a revolving way and have opposite revolving directions. The screw shell is rotated, and then the left guide screw and the right guide screw respectively drives the left slide rod, the right side rod, and the center slide rod to move along the horizontal direction so as to adjust the lifting of the large-tonnage supporting seat. The supporting seat causes that the left slide rod, the right side rod, and the center slide rod inwards or outwards displace in a horizontal way by exerting smaller force on the screw shell so as to increase or reduce the integral height of the supporting seat, thus causing that the bottom surface elevation of a carrier rises or reduces so as to meet the predicted height needed by the carrier.