This paper presents an approach of structure-preserving image completion with dynamic patches. Existing image completion methods may generate unnatural abnormal structures or structure disorders due to limited patches and patterns availability. Our structure-preserving image completion utilizes objective function minimization considering the coherence not only within the image cavity but also with global constraints. A series of dynamic patch-based optimizations are applied to fulfill the cavity. Unlike traditional fixed-size patch-based methods, our image completion with competitive dynamic patch-matching mechanism provides more effective structure restoration. Parallel searching of different-sized patches is performed to retrieve optimal patches for completing the image cavity with nice structure preservation. The experiments show that the realistic completed images by our approach are visually pleasing with nice structural coherence.