Abstract: The combined half-rotating wing (CHW) is a new power wing, which has important application prospect in bionic flight. A model of bionic CHW, which simulates bird, was proposed, formulas to calculate the model parameter were derived, and the method to reduce working gap of CHW was further given. The computational fluid dynamic models of CHW were established based on FLUENT software. The characteristics of lift change and of CHW were discovered after the numerical simulation of the flow field of the models. The results indicate that the distribution of velocity vector and pressure in the flow field are always affected by the Weis- Fogh effect within one motion period, and the Weis-Fogh effect can improve the lift of CHW greatly. Case study demonstrates that maximum lift can increase by 30.5%. The research results mentioned above can provide theoretical supporting to explain generating mechanism of lift for CHW, by which lift force can be estimated for CHW with different size parameters.