Motivated by the efficient movement of sea creatures, a novel conceptual design of bionic Unmanned Underwater Vehicle (UUV) was proposed in this article for the purpose of improving the propulsive performance of UUV based on traditional propulsion device, like propeller, etc. The current bionic UUV consists of two parts, the fuselage and four flexible foils. The former part serves as storage module, where the battery block and sensor devices are placed. The latter part functions as a propulsive module and the travelling wavy motion are adopted by the flexible foils. Moreover, three types of motion strategies are designed. Mode A, the foil 1# and foil 3# undergoes flexible motion while the other two remains stationary. Mode B, the foil 1# and foil 3# remains stationary while the other undergoes motion. Mode C, the four foils is in consistent flexible motion. The Computational Fluid Dynamic (CFD) method is utilized to make an evaluation on the propulsive performance of above three motion models. The systematic analysis is conducted on investigating the effect of motion parameters on propulsive performance of bionic UUV, hoping to provide some technical guidance for the future prototype testing. In addition, the typical vortex structures in the wake of bionic UUV are also presented and discussed.