The invention mainly relates to a passive residual heat removal circulating performance testing system. The passive residual heat removal circulating performance testing system comprises a residual heat removal circulating simulation system and an oversaturated pressure system, wherein the residual heat removal circulating simulation system comprises an in-pile heat source simulation module and an out-pile heat dissipation module; the in-pile heat source simulation module and the out-pile heat dissipation module are communicated through a pipeline to from a circulating testing loop; and the oversaturated pressure system enables pressure in the testing system to exceed saturated steam pressure of circulating liquid at a testing temperature. The in-pile heat source simulation module is used for simulating a heat source in an actual nuclear reactor; the volume flow of circulating liquid in the circulating testing loop, temperatures of inlet and outlet ends of the in-pile heat source simulation module and temperatures of inlet and outlet ends of the out-pile heat dissipation module are monitored so that the performance of the residual heat removal circulating simulation system can be obtained; and performances of the residual heat removal circulating simulation system actually arranged in the nuclear reactor can be tested in an accident process according to a performance testing result.