The invention relates to a passive residual heat removal heat exchanger testing device which comprises a heat transfer testing section, a voltage stabilizer, a shield pump, a heater, a circulation pump, a heat exchanger, a high-level water tank, a low-level water tank, a lifting pump, a water supplying pump and a spraying pump, wherein the heat transfer testing section, the voltage stabilizer, the shield pump, and the heater form a main loop system of the testing device; the heat transfer testing section comprises 3 C-shaped heat transfer pipes and a cooling water tank; the voltage stabilizer is connected with an outlet pipeline of the heat transfer testing section and an inlet pipeline of the shield pump; the shield pump is connected with the outlet pipeline of the heat transfer testing section; the flowing amount of a main loop is adjusted by adjusting a valve and a bypass valve in front of the shield pump; the heater is arranged between the shield pump and the heat transfer testing section. According to the device, the forms, sizes and materials of the heat transfer pipes are designed reasonably, so that the stress deformation problem can be reasonably avoided, the water use amount can also be greatly reduced, the heat transfer process can be simulated relatively accurately, and relatively accurate heat transfer data can be obtained.