Abstract: Birds are propelled and lifted by wings' flapping and rotating motion. In this study, the rotation amplitude and rotation time interval of wings were studied, the self-propelled flying motion of a three-dimentional(3D) bionic bird in a viscous flow is investigated numerically with a 3D computational fluid dynamics (CFD) package. The package includes the immersed boundary method (IBM), the volume of fluid (VOF) method, the adaptive multi-grid finite volume method, and the swimming and flying control strategy. It is suggested that the bird can fly faster forward or upward with an appropriate rotation amplitude and rotation time interval.