Based on the physical mechanism of the lightning upward leader inception from a wind turbine blade, the concept of downward leader tip critical distance is proposed. By solving downward leader tip critical distance, it can effectively determine the triggered lightning ability of wind turbine under atmospheric condition fluctuations and terrain feature differences. Analysis shows that when air pressure decreases, temperature increases, and humidity decreases, triggered lightning ability of wind turbine weakens to varying degrees. However, the combined effect of high air pressure, low temperature, and high humidity significantly enhances triggered lightning ability of wind turbine. At the same time, among the typical terrain features, wind turbine on flat plain has weaker triggered lightning ability, while those on symmetrical peaks or single slopes have a stronger triggered lightning ability. The ground inclination angle and the distortion of background electric field caused by the slope are key factors affecting triggered lightning ability of wind turbine under symmetrical peaks and single slopes. In addition, combined with complex terrain features, when wind turbine is located at symmetrical or asymmetrical peaks with large ground inclination angle, triggered lightning ability of wind turbine is greatly enhanced. The correctness of the analysis results related to triggered lightning ability of wind turbine mentioned above is also effectively verified. The relevant conclusions provide the necessary foundation and useful reference for studying triggered lightning characteristics and formulating corresponding lightning protection strategies for wind turbine in complex environments.