To enhance the accuracy of wind turbine wake simulation, a mass flux conservation equation was established based on wind velocity deficit distribution of power function and the Jensen wake model. Supplementary constraints were provided by the continuity equation and anisotropic empirical formulas, and to achieve a transition in wind velocity deficit shape from the near-wake to the far-wake region, a new three-dimensional wake model for wind turbines was proposed incorporating the assumption of Jiménez yaw wake center offset. Model accuracy validation was conducted using wind tunnel test data. Without considering yaw operation, the maximum fitting error in the near-wake region remained within 8%, while in the far-wake region, the simulation error was controlled within 5%. Under yaw conditions, the deflection of the wake center in the horizontal direction was described by the proposed model accurately. In the spanwise profile, the average absolute error between the proposed model and wind tunnel experimental data was within 5%. The validation results show that the proposed model accurately describes the downstream wind velocity distribution of wind turbines, both with and without yaw conditions.