The invention discloses a hydraulic plug pin ascending and descending device, and belongs to the field of self-ascending type ocean platform accessories. The hydraulic plug pin ascending and descending device comprises truss type pile legs, a ring beam, a lifting oil cylinder, a sliding beam, plug pin assemblies and plug pin mounting blocks; a plurality of plug pin holes which are matched with plug pin assemblies are uniformly formed in each chord rod; the plurality of plug pin holes are arranged in the length direction of each chord rod; the ring bean is arranged on the truss type pile legs in a sliding and sleeving manner; the plurality of the plug pin mounting blocks are respectively mounted on the ring beam; the plurality of the plug pin assemblies are respectively mounted on the respective corresponding plug pin mounting blocks; the plug pin assemblies and the plug pin holes are oppositely arranged at intervals; a plurality of sliding beams are respectively arranged on the respective corresponding chord rod in a sliding manner; one end of the lifting oil cylinder is mounted on the ring beam; the other end of the lifting oil cylinder is mounted on the sliding beam. The hydraulic plug pin ascending and descending device is low in assembling precision; the manufacturing cost is reduced.