Abstract: The benchmark problem computation is one of the main ways on verification test of nuclear power design and safety analysis software, but it has shortcomings of high cost, long cycle, and small number of benchmark problems. A new test method for neutron diffusion program was proposed in this paper, which takes the existing benchmark problem for the original test cases, produces more follow-up test cases based on metamorphic relationships contained in the physical model, and carries out metamorphic test verification on software. The example shows that this method can not only extend the number of benchmark problems, but also improve the adequacy of the test. It is a promising method for verification test.