Abstract: Vertical-axis wind turbines (VAWTs) have drawn much more attention in various application scenarios, due to their low construction cost and simple maintenance. However, the structural safety can be confined to the fluctuation behavior from the aerodynamic forces of VAWTs. This study aims to evaluate the structural safety of the turbine blades from the large-scale VAWT generator using numerical simulation software (ANSYS WORKBENCH). The aluminum blades of a 200 kW VAWT were taken as the research objects. The one-way fluid-structure interaction was used to combine the aerodynamics of the VAWT and the structural characteristics of a single blade. Specifically, a systematic calculation was performed on the structural deformations and stress concentration that generated by the blades of the 200 kW VAWT under the aerodynamic forces in the flow field at wind speeds of 10, 12, and 20 m/s and the cut-out wind speed of 25 m/s. Several aspects were covered, including the aerodynamic characteristics of the wind turbine rotor and a single blade under different wind speeds, as well as the pressure distribution of the cross-sectional airfoil at different azimuth angles, the deformation and stress distribution of a single blade in the wind turbine at different wind speeds, and the variation in the deformations and stresses that generated by the blades under the aerodynamic forces in the flow field with the azimuth angle. The distribution pattern was also explored for the deformations and stresses of the blade along the blade span direction and the specific positions of stress concentration. The main deformation directions of the wind turbine blades were determined in the three-dimensional flow field. The results show that the torque of a single blade fluctuated significantly, when the VAWT operating. The torque peaks of a single blade were concentrated on the windward side. The number of torque peaks in the one revolution of the wind rotor was consistent with that of the blades. There was the a great increase in the blade deformations and equivalent stresses, as the wind speed increased. The stresses of the blades were concentrated at the connection positions between the blades and the support struts. The deformations and stresses of the turbine blades reached the maximum at the cut-out wind speed. The maximum displacement of the deformation was approximately 8 m, and the maximum stress was 18.8 MPa. The deformation of the blade was distributed in a "W" shape along the span direction. The azimuth angle shared the three peaks during deformation. The maximum deformation occurred at the azimuth angle of 90°. The maximum stress of the blade was less than the yield stress of the 6061-T651 aluminum alloy material. The deformation of the blades mainly occurred in the direction of the incoming wind. This finding can also provide the strong support for the structural safety of the wind turbine blades in the hundred-kilowatt VAWTs.