Brake boosting system and self-propelled harvester

The utility model discloses a brake boosting system and a self-propelled harvester, and relates to the technical field of harvesting machinery. The brake boosting system comprises a hydraulic oil tank, a hydraulic pump, a brake pedal, a brake valve assembly and a brake cylinder. A piston rod is arranged in the hydraulic cylinder in a sliding mode and divides the hydraulic cylinder into a rod cavity and a rodless cavity, the piston rod is connected with the brake pedal, one end of the hydraulic pump is connected with the hydraulic oil tank, the other end of the hydraulic pump is connected withthe brake valve, the brake valve is communicated with the rod cavity, the rodless cavity is communicated with the brake cylinder, and the brake cylinder is used for braking wheels. Compared with the prior art, according to the brake boosting system provided by the utility model, the piston rod connected with the brake pedal and the brake valve connected with the hydraulic oil tank through the hydraulic pump are adopted; t