The invention belongs to the field of superconducting testing, and discloses a superconducting cable and
magnet low-
temperature testing device and method based on combined
refrigeration. The device comprises an outer Dewar used for providing a main body vacuum environment; the sample cavity is hung in the outer Dewar; the sample cavity comprises a cylindrical
barrel, two ends of the cylindrical
barrel adopt cover bodies with semi-
ellipsoid structures, or the whole sample cavity is in an
ellipsoid shape; the superconducting sample is hoisted in the sample cavity; the
liquid helium pipeline comprises an inlet
pipe and an outlet
pipe; one ends of the inlet
pipe and the outlet pipe are hermetically led out of the outer Dewar, and the other ends are connected with the sample cavity; the ends, led out of the outer Dewar, of the inlet pipe and the outlet pipe are connected with an
external liquid helium supply source and a
helium recovery device respectively. According to the invention, the
liquid helium pipeline realizes introduction of
liquid helium and
recovery of
helium, on one hand, a medium channel required by liquid helium cooling is provided for the superconducting sample, the
refrigeration requirement of low-
temperature testing is guaranteed, and on the other hand, working medium recycling is realized through helium
recovery, and liquid helium consumption and testing cost are reduced.