The invention relates to a low-temperature valve airtightness test device, and belongs to the technical field of technological equipment. The test device is mainly and technologically characterized by comprising a left vertical plate, an O-shaped sealing ring I, an inlet joint, an outlet joint, an O-shaped sealing ring II, a pressing base, an end cover, an ejector rod, a right vertical plate, a lock nut, a
handle, connecting bolts I, a guide groove, connecting bolts II, a supporting shaft, a bottom plate and connecting bolts III. The outlet joint, the left vertical plate and the right vertical plate are fixed to the two symmetrical ends of the upper end face of the bottom plate through the connecting bolts I, a connector with a guide
conical surface is arranged at the right end of the inlet joint, the O-shaped sealing ring I is installed in a groove in the right end face of the inlet joint, a connector with a guide
conical surface is arranged at the left end of the pressing base, the O-shaped sealing ring II is installed in a groove in the left end face of the pressing base, and the pressing base and the ejector rod are connected into a whole through the end cover. The low-temperature valve airtightness test device has the advantages of being compact and reasonable in structure, convenient and fast to use and maintain, capable of being reused, low in manufacturing cost and the like.