Based on the pile-rigid platform spatial simplified calculation model, and considering coordinate transformation matrix, we develope the space simplified method for general high-pile wharf under lateral loads, which is verified by examples of the upgrading project. The examples show that the lateral displacement and internal force result of the pile top by the 6-D space simplified method are close to the that by the finite element calculation, and the accuracy of the space simplified method can meet the structural design requirements. Based on five kinds of reinforcement programs, we draw the conclusion that the program strengthening at the sea side shall be consider in priority. The results indicate that the advantage is not obvious for the structure with double battered piles. Considering the arrangement and reducing the amount of construction, we recommend the program of vertical and battered piles.