Hydraulic transmission system and sanitation vehicle

The utility model discloses a hydraulic transmission system and a sanitation vehicle, the hydraulic transmission system adjusts electromagnetic force by controlling the current of a proportional displacement control valve, and further controls the displacement of a piston rod of a variable cylinder through the balance of the electromagnetic force and the acting force of a first elastic piece and a second elastic piece. Therefore, the displacement of the swash plate of the variable pump is controlled to adjust the displacement of the variable pump, the output flow of the variable pump is conveniently adjusted according to the change of the rotating speed of the engine, the rotating speed of the hydraulic motor is ensured to be constant, the actuating mechanism is in a stable working state, and the proportional speed regulation function of the hydraulic motor is realized through independent pump control. Compared with an existing hydraulic transmission system, a reversing valve is omitted, the valve control thr