Under the symmetry of the s+d mixed waves, a model is proposed which accounts for the combined influence of two factors on superconductivity. The first factor is the anisotropy of the pairing interaction between electrons, and the second is the Van Hove singularity in the two dimensional electronic structure. The theoretical results show that both the Van Hove singularity and the pairing interaction anisotropy are important factors to enhance Ｔc. The anisotropic pairing interaction naturally leads to the d-wave component. As this anisotropy strengthens, the d-wave component increases. The fairly high ratio of ２Δ（０）／ｋＢＴc of the high-Ｔc superconductors may be due to the fact that the weight of the s-wave component is far smaller than the weight of the d-wave component. The specific heat jump at Ｔc in combination model is completely different from the classical BCS theory.