In order to solve the problem of texture loss and image edge degradation, an improved anisotropic diffusion model is proposed in this paper. Firstly, the PM model and LCC model are combined. According to the changes of image gradient, the relationship between the gradient modulus of local image and the diffusion intensity is constructed. Different gradient modulus values are selected for different diffusion functions. Then, the -norm is used to determine the gradient threshold in the diffusion function, which further improves the generalization ability of the proposed model. Experimental results show that this model can not only solve the problem of outliers existing in the traditional PM model, but also effectively protect the integrity of image edge features and contour structure. Compared with the original algorithm, the image signal-to-noise ratio is improved by 1.47~1.57dB, and the structural similarity is improved by 17%, the denoising efficiency is improved while ensuring the denoising effect.