A new anisotropic diffusion filtering algorithm is proposed to reduce multiplicative speckle noise in SAR images. A new anisotropic diffusion equation that can strengthen edge is established by introducing the selfsnake diffusion into the diffusion equation of the classic SRAD and DPAD algorithms. Then, a new diffusion function that is estimated by improved Frost filtering coefficients is introduced into the new anisotropic diffusion equation, and it can effectively smooth speckle noise, preserve edges, and reduce blocking artifacts. The experimental results show that the proposed algorithm can outperform classic anisotropic diffusion equation in despeckling, preserving edges and reducing blocking artifacts.