Combined thread lifting device

The present invention discloses a combined thread lifting device and belongs to the field of ocean engineering equipment. The device comprises a pile leg and a jacking frame fixed to an ocean platform. A plurality of plug pin holes are formed in the pile leg. A first movable ring beam and a second movable ring beam movably sleeve the pile leg in sequence from up to down. The first movable ring beam is provided with a first plug pin oil cylinder assembly for insertion into any plug hole, while the second movable ring beam is provided with a second plug pin oil cylinder assembly for insertion into any plug hole. The device further comprises drive mechanisms, and lifting rods capable of rotating relative to the jacking frame and the ocean platform when driven by the drive mechanisms. Two axial ends of each lifting rod are rotatably mounted on the jacking frame and the ocean platform, respectively. Each lifting rod is provided in an axial direction of the lifting rod with a first thread portion and a second threa