The invention provides a hydraulic supporting device. The hydraulic supporting device comprises a rotary drum, a supporting device and a hydraulic pump, wherein the supporting device comprises a rotary shaft, a hydraulic chamber, fixed tubes and pistons, the hydraulic chamber is cylindrical, a round cavity is formed in the axial center of the hydraulic chamber, hydraulic oil is introduced into the fixed tubes through liquid inlets in the two ends of the hydraulic chamber and liquid inlet tubes connected with the liquid inlets via the hydraulic chamber, the tail end of each fixed tube is communicated with the corresponding liquid inlet tube, an opening is formed in the front end of each fixed tube, and the pistons are arranged inside the fixed tubes and are in sliding seal fit with the inner walls of the fixed tubes; the rotary shaft is located inside the round cavity and is in rotary connection with the hydraulic chamber, and the rotary drum is composed of two hollow fans and is welded to the side wall of the hydraulic chamber divided by the symmetrical fixed tubes. The motion of the pistons is controlled in a hydraulic mode, tension provided by the pistons enables friction between turfs to be increased, and then the turf on the outer circle is driven to be rolled up along with the movement of the rotary shaft.