With regard to the poor acceleration performance on GPU using the unstructured grids implicit method, this study realizes the GPU acceleration of LU-SGS implicit method based on unstructured grids with the cell-vertex scheme. With introduce the architecture of a GPU and its parallelization method, two grid reordering methods are set forth based on RCM and METIS, to improve data locality of unstructured grids and to improve acceleration performance on GPU using the unstructured grids implicit method. The ONERA M6 Wing test case is carried out to verify and validate this implementation. With two grid reordering methods, the GPU implementations achieve 63% and 69% improvements respectively. The GPU implementation obtains a speedup of 27 times compared to the CPU version running on a single core. It indicates that the proposed GPU implementation has a solid performance.