Abstract: The neutronics behavior of the test reactor core fuelled with natural uranium equivalent （NUE） was analyzed based on the neutronics design code system for CANDU reactor. The NUE two-channel test reactor core was demonstrated, and the analysis results were compared with the safety criteria and neutronics behavior of the corresponding fully natural uranium （NU） filled core to confirm the neutronics equivalence of NUE fuel. The study shows that NUE fuel filled in testing reactor meets the neutronics equivalence requirement. The test irradiation of NUE fuel in two channels of a CANDU reactor core with NU fuel is feasible in the neutronics design, and the introducing NUE has no impact on the core safety assessment.