An emergency escape structure of a variable amplitude oil cylinder crane for a ship comprises a driving cab seat, an escape port, an escape door device, a first escape ladder, a foundation pillar platform, an escape platform and a second escape ladder, wherein the driving cab seat is a foldable seat arranged in the middle of a driving cab of the crane; the escape door device is arranged at the bottom of the escape port; the escape port is formed in the bottom of the driving cab of the crane, located below the driving cab seat and communicated with the foundation pillar platform through the first escape ladder arranged blow the escape port; and the foundation pillar platform is arranged on the periphery of a foundation pillar of the crane, the escape platform is arranged on the foundation pillar platform, and the side part of the escape platform is communicated with a deck safety zone through the second escape ladder. During the use, a user firstly puts away the driving cab seat, then pushes a hand wheel to open a moving door and expose the escape port and reaches the deck safety zone through the escape port, the first escape ladder, the foundation pillar platform and the escape platform sequentially. By means of the design, people can escape when a driving cab window cannot be opened, and the safety performance is improved.