Low-temperature system for liquid-helium-free closed cycle sample test

The invention discloses a low-temperature system for liquid-helium-free closed cycle sample testing, which comprises a GM refrigerating machine, a vacuum container, a primary cold screen, a secondary cold screen, a condenser, a flow resistance element, a sample cavity, a circulating pump, a gas storage tank and a gas conveying pipeline, and the primary cold screen, the secondary cold screen, the condenser, the flow resistance element and the sample cavity are all positioned in the vacuum container; the GM refrigerating machine is fixed to the vacuum container, extends into the vacuum container and makes contact with the first-stage cold screen and the second-stage cold screen for cold conduction. According to the invention, the whole system forms closed circulation through the vacuum container and the gas transmission pipeline, no helium loss is caused during operation, the operation difficulty of an open liquid helium system and the waste of helium are avoided, the helium is cooled through the flow resistanc