The invention discloses a multilayer grating bearing cylinder and a preparation method thereof. The multilayer grating bearing cylinder is formed by nesting at least two single-layer grating cylinders, and the densities of the meshes of the adjacent single-layer grating cylinders are different. The preparation method for the multilayer grating bearing cylinder made from a composite material comprises the following steps: producing a wood pattern for casting a soft mode, producing a silicon rubber soft mode, assembling a mould, winding the soft mode in an assistance manner, carrying out vacuum bag moulding, demoulding and carrying out after-treatment, and integrally moulding the multilayer grating bearing cylinder; or preparing the single-layer grating cylinders according to the steps, and then assembling the single-layer grating cylinders into the multilayer grating bearing cylinder. The preparation method for the multilayer grating bearing cylinder made from metal or engineering plastic comprises the following steps: preparing a casting mould for the disassembly components of the single-layer grating cylinders, melting and casting, welding, and then assembling the single-layer grating cylinders into the multilayer grating bearing cylinder; or moulding in one step by a 3D printing technology. The multilayer grating bearing cylinder has the characteristics of good structural stability, light mass, high mechanical properties, difficulty of structural overall buckling instability, simple and practicable preparation method, and low cost.