Abstract: The aerodynamic characteristics of a novel coaxial counter-rotating double vertical axis wind turbine（CCRD-VAWT） were studied, the aerodynamic loads of the novel wind turbine were obtained by solving the threedimensional unsteady Navier-Stokes equation, the validity of the research method was verified by comparison results with the experiment data. The research results show that the power coefficient of bottom rotor of the CCRD-VAWT is 0.3% higher than that of the single vertical axis wind turbine（VAWT）, and the power coefficient of the top rotor is increased by 3.2% compare to that of single VAWT. The wake velocity deficit of CCRD-VAWT is larger than that of the single VAWT; it has a great advantage in the terms of deploying wind turbines in wind farm. When tip speed ratio is 4, the variation of the complex eddies inside the CCRD-VAWT is very fierce. These fierce changes will have a greater impact to the variation of wind turbine wake. In addition, the changes of tip vortex in the wind turbine are not as obvious as that in a single VAWT.