The utility model discloses a low-temperature constant-humidity test system for sulfur hexafluoride gas analysis, and relates to the field of electrical tests. At present, the change of temperature and humidity has obvious influence on the test result of a sulfur hexafluoride gas analysis and test instrument, and particularly, the sulfur hexafluoride gas analysis and test instrument cannot work normally in a high-temperature and low-humidity test environment in summer. The device comprises a box body, a box door positioned in front of the box body, a physical refrigeration module arranged in the box body, a temperature measuring device, a constant humidity device, a test instrument and sulfur hexafluoride inflatable equipment communicated with the test instrument through a pipeline, wherein the box body is composed of double layers of plates, a thermal insulation material is filled between the plate layers, a hollow support is arranged in the box body, the hollow support divides the internal space of the box body into an upper layer and a lower layer, the upper layer is a refrigeration chamber, the lower layer is an instrument chamber, the test instrument is arranged in the instrument chamber, and the physical refrigeration module is arranged in the refrigeration chamber. According to the technical scheme, the test environment in the box can be maintained for a long time, the test stability is good, and the progress of maintenance work can be effectively guaranteed.