In recent years, affected by extreme weather, frequent wildfires have led to a significant increase in wildfire tripping incidents in the Southern Power Grid. To investigate the main influencing factors and their mechanisms behind wildfire tripping of transmission lines, data on wildfire warnings and tripping incidents along transmission corridors in Southern Power Grid region over the past five years are collected. Statistical analysis is conducted from both temporal and spatial dimensions, incorporating factors such as climate, terrain, and surface vegetation. Additionally, the concept of "transmission line wildfire tripping sensitivity" is proposed to represent the probability of wildfire-induced tripping per unit of wildfire warnings, effectively avoiding the logical fallacy of "correlation implies causation" in statistical analysis. Finally, by integrating flame spread models and air breakdown models, the underlying physical mechanisms of environmental factor influences are thoroughly analyzed. The results indicate that although wildfire warnings and tripping incidents in Southern Power Grid have increased year by year, thanks to diversified wildfire monitoring methods and timely firefighting measures, the overall wildfire tripping sensitivity has shown a declining trend annually. The findings of this study will assist grid operators in developing more targeted and differentiated wildfire management strategies based on field conditions.