Cold end of low-temperature high-pressure plunger pump

The invention belongs to the technical field of low-temperature high-pressure plunger pumps, and particularly relates to a cold end of a low-temperature high-pressure plunger pump. The cold end comprises a cold end shell body, a plunger and a cylinder sleeve, wherein the plunger is arranged inside the cylinder sleeve, the cylinder sleeve is located inside the cold end shell body, a connecting locking device is arranged at the front end of the cold end shell body, the cold end shell body comprises a left cavity and a right cavity which communicate with each other, the right cavity internally comprises the cylinder sleeve, a valve set and a discharging flange, and the valve set comprises a valve seat, a high-pressure valve arranged in the valve seat and a low-pressure valve arranged betweenthe cylinder sleeve and the valve seat. According to the cold end of the low-temperature high-pressure plunger pump, the novel valve set structure adopts metal sealing, continuous opening and closingof the high-pressure valve and the low-pressure valve are achieved, and normal-pressure ultralow-temperature liquid nitrogen is converted into high-pressure low-temperature liquid nitrogen and is discharged so that the requirement for high-frequency opening and closing can be met, the characteristics of being low in conveying medium temperature and high in output pressure are achieved, and the problem that a common plunger pump cannot pump the low-temperature and high-pressure liquid nitrogen is solved.