The superconducting accelerating segment in injectorⅡof Accelerator Driven Sub-critical System(ADS) uses superconductingcavities whose frequency are 162.5 MHz. The vertical performance of superconducting cavity devicesmust be tested at liquid helium temperature(2, 4.2 K) before being assembled in cryostat. To meet the runninggoal of the 0 25 MeV linac system, it is necessary to build a set of cryogenic testing system for superconductingcavity, which is used to test the performance of the superconducting cavity and whether cavity meet the designgoal.