Hydraulic underground brake device for cable logging tractor

The invention discloses a hydraulic underground brake device for a cable logging tractor. The hydraulic underground brake device solves the problems that an existing device is complex in structure, inconvenient to control, large in occupied space and prone to brake locking. According to the technical scheme, the device comprises a hydraulic push rod assembly connected with a tractor oil way and supporting arms, the supporting arms are symmetrically arranged on the two sides of a push rod of the hydraulic push rod assembly, the rear ends of the supporting arms are hinged to a support at the front end of the hydraulic push rod assembly, and damping rolling wheels are arranged at the front ends of the supporting arms; guide grooves are formed in the supporting arm in the axial direction, a sliding block is arranged at the front end of the push rod, guide blocks are symmetrically arranged on the two sides of the sliding block, and the guide blocks are located in the guide grooves in the corresponding sides. The d