Abstract: A circulation distribution of bionic blades from hydraulic torque converter was established based on fish bodies. The reverse engineering was used to extract fish bodies' elements, and circulation distribution schemes of every impeller blade were proposed and then bionic blades models were established. A detached eddy simulation based on Smagorinsky sub-grid stress model was adopted to numerically calculate three-dimensional flow fields of channel models for bionic blades and original blades respectively. Finally, the results reveal that the numerical simulation is effective through comparative analysis of simulation and experiment results from original blades; bionic blades designed from bionic circulation distribution possessing excellent drag reduction performance can increase the highest efficiency in the case that the major parameters of original blades don't be changed. The highest efficiency can be increased by 1.5 percent from original hydraulic torque converter; the flow conditions of bionic and original fields were analyzed contrastively. The Rothalpy was used to compare energy loss of two kinds of blades. The results agree with predicted values. It also shows the bionic method is feasible and valid for blades designing.