The utility model relates to a marine automatic re -setting hydraulic damper. It has solved the unable automatic re -setting scheduling problem of attenuator for the existing ship. Including damping cylinder body, first column passageway, second column passageway, annular table rank, piston rod, auxiliary piston pole, bush and cylinder cap, form an annular gap between the second column pole one end circumference outside and the bush, form the 2nd annular gap between the other end circumference outside and the annular table rank, and be equipped with reset structure between piston rod and the auxiliary piston pole. The advantage lies in: simple structure, stability is good, and sensitivity is high, and is the motion interval of piston rod 6 20 the operation of millimeter scope makes the stroke of this attenuator little like this, can reach 100 tons load, and just the small boats and ships usefulness that is applicable to will satisfy the load requirement simultaneously, and can carry out automatic re -setting through the spring, and it needs external force to carry out the trouble that resets to have solved traditional attenuator, and is convenient for install.