The invention relates to a passive residual heat removal cycle performance testing method. A testing system in the passive residual heat removal cycle performance testing method comprises a residual heat removal cycle simulation system and a supersaturated pressure system, wherein the residual heat removal cycle simulation system comprises an in-pile heat source simulation module and an out-of-pile heat dissipation module; the in-pile heat source simulation module and the out-of-pile heat dissipation module are communicated through a pipeline and form a cycle testing circuit; the supersaturated pressure system enables the pressure in the testing system to exceed saturated vapor pressure of cycle liquid under a testing temperature. In the passive residual heat removal cycle performance testing method disclosed by the invention, the in-pile heat source simulation module is used for simulating a heat source in an actual nuclear reactor, the performance of a residual heat removal cycle simulation system can be obtained by monitoring a volume flow rate of the cycle liquid in the cycle testing circuit, the inlet and outlet temperature of the in-pile heat source simulation module and theinlet and outlet temperature of the out-of-pile heat dissipation module, and the performance of the residual heat removal cycle system allocated in the actual nuclear reactor in an accident can be verified through a performance testing result.