Urea nozzle system capable of preventing crystal blockage

The embodiment of the utility model discloses a urea nozzle system capable of preventing crystal blockage. The urea nozzle system is used for reducing the situation that crystals are generated at the joint of a urea nozzle and a catalytic converter. According to the method, a catalytic converter, a urea nozzle, a heat insulation gasket, a urea injection pipe, a cooling liquid inlet pipe and a cooling liquid return pipe are included; the urea nozzle is connected with the catalytic converter through the heat insulation gasket; the urea nozzle is provided with three openings which are respectively connected with the urea injection pipe, the cooling liquid return pipe and the cooling liquid inlet pipe; a connecting port of the urea injection pipe and the urea nozzle is arranged at the highest position, and a first straight pipe section is arranged at the joint of the urea injection pipe and the urea nozzle; the position of the cooling liquid return pipe is higher than that of the cooling liquid inlet pipe; a seco