A damping hinge device includes a hinge and a damper. The damper is arranged coaxially with the hinge and has a damping shell, a damping body, a plurality of rotating slices, a plurality of limiting slices, an outer gasket and a pushing body. The damping shell has a cylinder-shaped shell body, a top cover is formed in the top of the shell body. The damping body is accepted in the damping shell and has a basic portion and a column portion extending from one end of the basic portion. The rotating slices are accepted in the damping shell and fixed around the column portion. The limiting slices are fixed in the damping shell and rotatably around the column portion of the damping body, the limiting pieces and the rotating pieces are staggeredly arranged. Damping oil is filled between the adjacent limiting slices and the rotating slices. The outer gasket is disposed on the basic portion of the damping body and pressed against the shell body.