Vehicle urea is a chemical added to special SCR system. It can automatically control the emission of proper amount of urea for vehicles according to the concentration of nitrogen oxides in the exhaust gas discharged by the engine, so as to reduce the concentration of nitrogen oxides and make the exhaust gas reach the cleanest state containing carbon dioxide and water. Generally speaking, the urea tank of passenger cars is hidden at the bottom, while the urea tank of trucks is generally installed next to the fuel tank, which should be protected from light, usually black or dark. However, it should be noted that vehicle urea cannot be directly added to the fuel tank. All urea solutions used in vehicles are equipped with filling pipes, which need to be used to fill urea solutions for vehicles into urea self-storage tanks on vehicles. Urea for vehicles is an essential product for heavy-duty diesel vehicles to meet national emission standards. Its concentration is 32.5%, and it is an aqueous urea solution with ultrapure water as solvent. Raw materials are urea crystals and ultrapure water. In order to meet the national emission standards, heavy trucks, buses and other diesel vehicles need to choose a suitable SCR system for tail gas treatment, and this system must use urea solution to treat nitrogen oxides in tail gas. Therefore, vehicle urea solution has become an essential product for heavy trucks and buses to meet the national emission standards.