Abstract: The Green's function in Cartesian geometry can be used to replace the complex Green's function in cylindrical geometry when solving the neutron diffusion equation in cylindrical geometry. The nodal Green's function method for cylindrical geometry based on Green's function in Cartesian geometry (RNGFM) and the nodal Green's function method for cylindrical geometry based on Bessel function(CNGFM) are compared in the paper. The result indicates that the advantage of RNGFM is the simplicity of formulation, while the iteration process of CNGFM costs less time._