The invention discloses a novel pile foundation underpinning structure and method. The method comprises the following steps: step 1, a new pier pile foundation is constructed; step 2, a temporary support is mounted on a new pier bearing platform, and the load on the upper part of a bridge is transmitted to the lower part through the novel pier pile foundation by the temporary support and a jack; step 3, an old pier is dismantled and an old pile foundation is removed; step 4, a new bearing platform is constructed and connected with the new pile foundation, and a new pier is constructed on the new bearing platform; step 5, the load on the temporary support is transferred to the new pier by utilizing the jack, a support frame and the like; step 6, the temporary support is dismantled. The structure stress is clear, the structure doesn't relate to the original lower part structure, the construction difficulty is relatively low, the landscape of the bridge is not influenced, the support constructed by utilizing the new pile foundation is more reliable, and the novel pile foundation underpinning structure and method solve the problems that the traditional pile foundation underpinning is large in foundation pit excavation, high in risk, cost and construction difficulty, incapable of removing the old pile foundation, and the like.