In order to improve stall characteristics more effectively or eliminate dynamic stall in a revolution of vertical axis wind turbine, three kinds of novel flow-deflecting-gap (FDG) blade were designed and investigated numerically, including two-side FDG blade, toward-outside FDG blade and toward-inside FDG blade. Firstly, the aerodynamic characteristics of isolated flow-deflecting-gap blade were obtained and its effect was illustrated. Then, the investigation on aerodynamic characteristic of novel SB-VAWT was conducted. The obtained results indicated that compared to clean airfoil, FDG enhances the stalling angle of attack (AOA) by 2 degrees and increases lift-drag ratio at high AOA. Furthermore, FDG significantly decreases the frequency of vortex shedding and greatly reduces amplitude of lift oscillation. Fora vertical axis wind turbine, toward-inside FDG can efficiently decrease the optimal tip-speed ratio and improve the aerodynamic performance at low tip-speed ratio. Additionally, an increase of 10.21% of torque coefficient is caused by toward-inside FDG. Jet flow in FDG towards leading edge offsets the swirling flow over the suction surface and the trailing-edge vortex produced by bluff edge is also weakened or even eliminated by FDG. (C) 2020 Elsevier Ltd. All rights reserved.