processing.Through the contrastive analysis of the hydrodynamic performances of bionic,combinational and Conventional blades in changing pitch angle,then we can draw a conclusion,that at the rated speed,when the pitch angle of bionic blade and combinational blade respectively is at 70and 60,the torque of turbine reaches its maximum and exceeds that of the standard blade,besides comparing the former two kinds of blades,the performance of bionic blade is the best.Apart from that,the analysis of the pressure and velocity fields of different blades come to the same conclusion. On the basis of numerical simulation,this thesis designs a variable pitch system controlled by wireless steering engine.This design includes the study of variable pitch moment and driving mode,the design of the system principle diagram and three-dimension modeling and so forth.Then the modal of bionic blade and combinational blade are produced,the variable pitch system is worked out and assembled,the experiment equipment and experiment scheme is well prepared,at last the test on the hydrodynamic performances of the turbines constituted by different blades is carried out underwater.The experimental results expected coincide with the results of the numerical simulation,their trends are similar,besides we get the important data-the rotate speeds of the turbine at different pitch angle and the same rated speed. In a word,the study of this thesis provides reference for the selection of bionic airfoil of turbine blade,and shed new light on the design of tidal current turbine blade, revealing the importance of bionics in engineering design,having positive influence and guidance on the development,utilization and promotion of ocean.Meanwhile,the research method and data results of this thesis are valuable reference for the further study on the application of bionics in tidal current turbine. Key words tidal energy;turbine;bionic shark fin;airfoil;variable pitch system 万方数据processing．Through the contrastive analysis of the hydrodynamic performances of bionic，combinational and Conventional blades in changing pitch angle，then we can draw a conclusion，that at the rated speed，when the pitch angle of bionic blade and combinational blade respectively is at 700and 600．the torque of turbine reaches its maximum and exceeds that of the standard blade，besides comparing the former two kinds of blades，the performance of bionic blade is the best．Apart from that，the analysis of the pressure and velocity fields of different blades come to the same conclusion． On the basis of numerical simulation，this thesis designs a variable pitch system controlled by wireless steering engine．This design includes the study of variable pitch moment and driving mode，the design of the system principle diagram and three-dimension modeling and SO forth．Then the modal of bionic blade and combinational blade are produced，the variable pitch system is worked out and assembled，the experiment equipment and experiment scheme is well prepared，at last the test on the hydrodynamic performances of the turbines constituted by different blades is carried out underwater．The experimental results expected coincide with the results of the numerical simulation，their trends are similar,besides we get the important data-the rotate speeds of the turbine at different pitch angle and the same rated speed． In a word，the study of this thesis provides reference for the selection of bionic airfoil ofturbine blade，and shed new light on the design oftidal current turbine blade， reveal ing the importance of bionics in engineering design，having positive influence and guidance on the development，utilization and promotion ofocean．Meanwhile，the research method and data results of this thesis are valuable re诧rence for the further study on the application of bionics in tidal current turbine． Key words：tidal energy；turbine；bionic shark fin；airfoil；variable pitch system 万方数据