A new type of casing pipe pile foundation is presented to increase the offshore pile foundation lateral capacity or decrease the lateral displacement. The nonlinear response of the casing pile under lateral load is studied by means of p-y curves. The influence to the pile response of the depth below the seafloor and the width of the casing pipe is investigated and compared with the common pile. The results show that the casing pipe can excite the pile-soil interaction effectively and increase the pile foundation capacity and decrease its response to lateral loads.