TRUCK CRANE; IT IS THE FIRST SMALL TONNAGE CRANE THAT A HITCHING DEVICE IS USED IN AN AUXILIARY SYSTEM TO SATISFY THE HARSH REQUIREMENTS FOR AXLE LOAD IN DIFFERENT AREAS, A QUICK CONNECTOR IS ADOPTED TO REALIZE QUICK INSERTING AND PULLING. PRESSURE CUTOFF VALVE WITH SPECIAL STRUCTURE IS ADOPTED TO AVOID THE PRESSURE IMPACT DURING OPERATION AND ELIMINATE THE SHAKING DURING HOISTING.