The utility model discloses a firm string tension structure of multistage car spoke formula, including rigidity outer loop, flexible cable inner ring system, wind up firm roof beam system and last quarter tensioning cable rod system the firm roof beam system of winding up below is provided with one at least flexible cable zhonghuan, flexible cable inner ring system comprises upper portion inner ring cable and lower part inner ring cable, the firm roof beam system of winding up comprises a plurality of reinforcing beams, last quarter tensioning cable rod system include a plurality of settings at the multistage cable that corresponds the reinforcing beam below be provided with vertical vaulting pole between flexible cable zhonghuan and the reinforcing beam, be provided with vertical vaulting pole at cables at different levels between the reinforcing beam respectively with corresponding. The utility model discloses mainly resist external load with the axial force, the atress is efficient, and rigidity is big, is favorable to reducing NULL, and local moment of flexure can be undertaken to the reinforcing beam to make the roofing can adopt multiple surface modeling, be convenient for adopt the rigid roof board, have extensive suitability in large -scale public building such as stadium, football court.