A method for constructing a cage body of a tapered cage assembled in a rigid-flexible manner includes steps as follows. A cage body of a tapered aquaculture cage is assembled by combining a rigid-structure copper alloy stretched mesh and a flexible synthetic fiber mesh. Pipe rings mounted on the standard component of the synthetic fiber mesh are mated in a staggered manner with plugging rings on the standard component of the copper alloy stretched mesh, and high-performance synthetic fiber rope is rove through the pipe rings and the plugging rings； in this way, the connection is completed. The cage effectively improves the cage resilience under the ocean current condition, avoids mesh sheet deformation or corner breakage, enhances the water exchange capability in and out of the cage body of the gravity cage, and effectively improves the growth environment for the fishes farmed in the cage body.
