The invention provides a curved structure comprising a plurality of snake bone middle sections, snake bone middle columns and connecting ropes, wherein each snake bone middle column includes snake bone middle columns 1 and 2. A layer of snake bone middle columns is staggered in the symmetrical direction between the adjacent snake bone middle sections, the snake bone middle column 1 is arranged between the snake bone middle sections at one end of a snake bone, the snake bone middle columns 1 and 2 are alternately arranged in three directions between the snake bone middle sections at the other end, the snake bone middle column 1 is always used in the other direction, and the center of each snake bone middle section is provided with a first center hole. Four small holes for the connecting ropes to penetrate are evenly formed in the wall thickness direction. The center of each snake bone middle column is provided with a second center hole, the second center holes and the small holes of thesnake bone middle sections are in staggered series connection through the connecting ropes, and by control of the extension of the connecting ropes, the snake bone middle sections are driven to deviate with the snake bone middle columns as fulcrums. The invention also provides a corresponding insertion hose and other devices. By adoption of the technical scheme, the problems in the prior art thata curved structure is complex in structure and the bending angle cannot be accurately controlled are solved.