Abstract: The development of centrifugal pumps follows the prevailing trend toward larger size, higher flow rate, and greater power. However, most related studies are still conducted on model pumps. So far, few investigations have been carried out on the performance of prototype pumps, particularly regarding their fluid-solid coupling characteristics. Accordingly, to examine the structural stress and deformation distribution in large centrifugal pumps, a oneway fluid-solid coupling method was employed to numerically simulate and analyze the stress-strain characteristics of largesize centrifugal pumps with different guidevane arrangements. The results show that: ① The maximum deformation, stress, and strain in both the fixedguidevane and flexibleguidevane centrifugal pumps occur at the impeller outlet. ② Compared with the fixedguidevane configuration, the circumferential nonuniform distribution is significantly reduced after installing flexible guide vanes, whereas the maximum values increase. ③ In the fixedguidevane centrifugal pump, as the flow rate increases, the maximum deformation gradually decreases, while the maximum stress and strain gradually increase. In the flexibleguidevane centrifugal pump, the maximum deformation, stress, and strain all gradually decrease with increasing flow rate. The maximum values in the flexibleguidevane pump are notably higher than those in the fixedguidevane pump.