The Towable Lavatory Service Truck is a self-propelled special ground equipment at the airport that provides toilet flushing water to aircraft and receives sewage from aircraft toilets through on-board equipment. The water tank is made of high-quality food-grade stainless steel plates and is firmly welded by argon arc welding. High-quality food-grade stainless steel water pumps are used. A vacuum pump is configured for simple and convenient operation. Water level displays and flowmeters are configured to make operations simpler and more convenient. According to customer needs, a heating inner tank insulated water tank, which is the first of its kind in China, can be configured.