Abstract: In this paper, we propose a general direct discontinuous Galerkin (GDDG) method based on Taylor basis functions for diffusion equations on arbitrary polygonal meshes. The mesh can be composed of distorted quadrilaterals or arbitrary polygons. Numerical experiments show that the GDDG method can effectively solve diffusion equations on arbitrary polygonal meshes. Specifically, the algorithms in group A achieve optimal (k+1)th order convergence in the L² norm and optimal k th order convergence in the H¹ norm, while the algorithms in group B achieve optimal H¹ convergence, and achieve optimal L² convergence with specific parameter selection. Through theoretical analysis and numerical experiments, the optimal selection of parameters for the GDDG method is proposed. Subsequently, the method is tested on diffusion problems with variable diffusion coefficients and anisotropic diffusion, demonstrating the applicability of the GDDG method to general diffusion problems.