As energy saving device, the vane wheel located in the downstream of propeller recovers energy from propeller wake. The deformations on the vane wheel are studied in present study considering Two-way fluid-structure interaction. The distributions of deformation and subsequent hydrodynamic performance change are discussed in present study. Results show that the numerical method employed in present study is reliable. The blade tip of vane wheel suffers severer deformations. The structural stress is concentrate at the interface of inner part and outer part.