Objective: Although existing research on conductor fatigue life has established a corresponding theoretical basis and provided core support for subsequent calculation work, two key issues remain in engineering applications. First, although the combined dynamic effects of wind speed and direction in the field environment are critical to the actual fatigue evolution process and service life of conductors, existing models insufficiently consider this factor, leading to discrepancies between life predictions based on theoretical calculations and actual engineering observations. Second, the existing theoretical system for fatigue life calculation is complex, requires specified calculation methods, and demands high levels of professional and technical knowledge from customers. As a result, wide promotion and efficient application in the power industry—especially in grassroots operation and maintenance units—are difficult, restricting the transformation of theoretical results into engineering practice. To address these problems, this study proposes a method for evaluating conductor fatigue life based on the probability distributions of wind speed and direction. Methods: Transmission lines in Northwest China were selected as the research object. More than 10 years of meteorological data from this region were systematically collected and analyzed, and the probability density functions of wind speed and wind direction were accurately obtained. Considering the key factors such as conductor type, span, and tension, more than 40 000 finite element models of conductor-insulator string suspension systems were constructed. Three typical conductors corresponding to maximum, median, and minimum frequencies were selected for fatigue analysis based on the first-order positive symmetrical side-bending frequency of the conductor. Nonlinear dynamic response analysis was then carried out for these conductors, and their stress time histories were extracted. Finally, the annual fatigue performance of different conductors was evaluated using the Wöhler safety curve, the rain flow counting method, and Miner's linear cumulative damage theory based on the measured wind speed distribution. Results: The analysis showed the following results: (1) Monitoring of local meteorological conditions revealed that the dominant wind direction in the study area was southeast, and the wind speed distribution conformed to the generalized extreme value distribution with a position parameter of 2.507, a shape parameter of 0.080, and a scale parameter of 1.440. (2) Stress time histories were extracted at the suspension point edge (40 cm), the 1/4-span position, and the midspan position. The stress level at the suspension point edge was considerably higher than that at other positions, and the average stress of the conductor increased with decreasing natural frequency and increasing wind speed. (3) The degree of wind-induced fatigue damage was closely related to the conductor's natural frequency and the ambient wind speed. The lower the natural frequency was, the greater the fatigue damage, especially at higher wind speeds. A fatigue performance database of transmission lines was finally established based on conductor parameters. Conclusions: The findings of this study provide an efficient and practical tool for transmission line operation and maintenance. By entering key parameters such as conductor type, tension, and span and combining them with regional wind speed and direction data, the method enables rapid estimation of conductor fatigue life, scientific assessment of remaining service life, proactive maintenance of high-risk line segments, and significant improvement in the operational efficiency of transmission line maintenance. Its application contributes to ensuring the safety and stability of power system operation.