The invention provides a caisson structure with a wedge-shaped bottom wall. The caisson structure can be inserted into a notch in the front end of a port. A caisson comprises a plurality of caisson bin boxes which are connected side by side. Each caisson bin box comprises an inner wall, a front wall and a bottom wall, wherein the bottom wall is in a wedge shape, the inner wall is tangent to the side face of the notch of the port, the bottom wall is tangent to a foundation bed of the port, and therefore the sliding-resisting and capsizing-resisting stability of a wharf structure is improved. The bottom walls of the caisson bin boxes are in the wedge shape, the gradient of the bottom walls of the caisson bin boxes is consistent with that of a slope, the bottom walls of the caisson bin boxes are inserted into the notch of the foundation bed, the caisson structure and the foundation bed interact to resist the horizontal force of a wharf, the integral center of gravity of backfill in a caisson body is moved backwards, and the capsizing resisting stability is improved.