Abstract: The blade element theory was used to design tidal current turbines in this study to improve their hydraulic performance and meet the growing need of tidal current energy utilization. We adopted a correction factor to optimize the chord length and setting angle of the blades and obtained a new horizontal axis tidal current turbine of better hydraulic performance. This new turbine was simulated using a CFD code. Results show that it has a high power factor in the rated condition. Analysis of the flows in the internal and external channels of the turbine reveals that the flows have excellent three-dimensional characteristics, free of local separation or reverse flow.