Focusing on the issue that the computation of the optical flow has a weak robustness to the edge diffusion, noise and outliers of the visible flow image, an improved approach of physics-based optical flow computation is developed to enhance the robustness of the optical flow computation. The proposed algorithm introduces the anisotropic filter into the method of the physics-based optical flow to improve the robustness of edge optical flow, and integrates the penalty factor into this approach to reduce the effect of noise and outliers on the optical flow computation. Then, the energy function of optical flow is minimized by using variation principle to solve the Euler Lagrange equation. Finally, the velocity field is obtained by exploiting the iterative method.Simulation results show that, compared with the traditional Lucas-Kande, Horn-Schunck, Pyramid Lucas-Kande, and the physics-based optical flow computational methods, the proposed algorithm can significantly reduce the diffusion of optical flow on edges and in corners, improve the robustness to noise and outliers, and thus obtain a velocity field with higher robustness.