Steel-lined plastic multi-valve water jet vacuum units weld steel mesh to the surface of the steel body, using pure polyethylene (PE) as raw material and combining steel plates, steel mesh, and PE into one by rotational molding technology. The PE is firmly bonded to the steel body surface. The steel-lined plastic multi-valve water jet vacuum units offer benefits such as seamless welding, no leakage, resistance to aging and impact, long service life, and compliance with hygiene standards. They address the shortcomings of plastic rotational molding storage tanks, such as poor rigidity and strength, low pressure resistance, and poor temperature resistance. The inner lining of the product is flat, smooth, and strong, and compared to traditional steel-lined plastic plate water tanks, steel-lined rubber storage tanks, and steel-lined glass fiber reinforced plastic storage tanks, it does not leak, does not peel off, can withstand certain pressure, can withstand higher temperatures, and has a long service life. The steel-lined plastic multi-valve water jet vacuum units can be customized according to customer requirements and can be used in parallel with two or more vacuum pumps.