The invention relates to a hydraulic U-type steel bracket supporting machine, which effectively solves the problems of slow installation, high danger, low production efficiency and the like when a U-type steel bracket is supported in a roadway which is supported by the U-type steel bracket. A grasping mechanism is arranged above a travelling mechanism and is connected with the travelling mechanism; the travelling mechanism is arranged at the upper part of a rack; the lower part of the rack is connected with a rotary disc mechanism; the rotary disc mechanism is connected with a lifting mechanism; and the grasping mechanism, the travelling mechanism, the rotary disc mechanism and the lifting mechanism are all connected with a control mechanism. With the adoption of the supporting machine using hydraulic pressure as power, hydraulic resources in a mine are fully utilized, therefore, the use is safe, the installation is quick, and the production efficiency is improved.