The invention discloses a hat type cylinder bottom and particularly relates to a hat type cylinder bottom provided with an oil way. The hat type cylinder bottom is used for an ultra-hydraulic oil cylinder. The hat type cylinder bottom is composed of a pin shaft 1, a cylinder bottom body 2 and a positioning sleeve 3. The hat type cylinder bottom is formed through one-time forging and pressing by a die, and the compactness of internal crystalline grains of the cylinder bottom can be improved. Compared with an existing product, the hat type cylinder bottom is convenient to use, simple in structure and low in cost; the working stability of hydraulic cylinders of the type is improved, and the problems of oil leakage and the like due to welding damage can be avoided.