1. The structure and working principle of hydraulic transmission and components; 2. Demonstration control experiment of hydraulic bulldozing machinery; 3. Demonstration control experiment of hydraulic bulldozer 4. Shoveling action of hydraulic bulldozer; 5. Earth-moving action of hydraulic bulldozer; 6. Unloading action of hydraulic bulldozer; 7. The hydraulic bulldozer returns when it is empty;