Wind power devices are now used to produce electricity, and commonly termed wind turbines. Load and performance calculations of wind turbines are usually performed by the Blade-Element/Momentum (BEM) method. However, the wake effects and the wake-blade structure interactions are less considered in most wind turbine analysis. This research studied a dynamic wake and blade interacted wind turbine. The finite state dynamic wake theory was applied. The effects of the wake and the configuration of the modern trailing-edge-flap (TEF) on the wind turbine blade were analyzed. The lift and the stress distribution on the blade were performed by using semi-analytic and numerical wake theory (The finite state wake theory) and the combination with APDL (ANSYS Parametric Design Language) and FORTRAN code. The effects of TEFs, considering their span-wise lengths and index angles on wind turbine blades, were fully discussed. The thrusts and root stresses on the wind turbine blade were also presented. Results show that with identical shape and material of blades, installing TEF could increase the lift (thrust), while no significant rise in stress are produced at the root section of the blade.