A hydraulic cylinder cushion device installed in a hydraulic cylinder provided, in which a rod performs reciprocating movement in a cylinder tube, and which discharges high-pressure hydraulic fluid that is formed in pressure chambers between a piston and a head cover and between the piston and a cover end during a stroke-end operation. The hydraulic cylinder cushion device includes a check ring which is installed in a groove provided on an inner surface of the head cover or the cover end, and moves to one side in the groove so as to close a flow path during rushing into a stroke end while it moves to the other side in the groove so as to open the flow path during an initial operation in the stroke end.