To promote biodiversity conservation and ecosystem restoration in the Meigu Dafengding National Nature Reserve of Sichuan Province, based on a 25 hm² sample plot established in the reserve, the driving effects of topographic factors on the species diversity pattern of woody plants were investigated by analyzing the impacts of topographic factors ［slope (θ), aspect, and position］ on woody plant species composition, α diversity indices, and β diversity indices. The results show that there are 42 096 woody plant individuals belonging to 211 species in 59 genera of 32 families in the Meigu Dafengding National Nature Reserve of Sichuan Province, and the areas with the highest species numbers across different slopes, aspects, and positions are slope Ⅱ (5°<θ≤15°) (187 species), west slope (211 species), and lower slope (210 species), respectively. The Margalef richness index and Shannon-Wiener diversity index generally show a tendency of “increase-decrease-increase” with increasing slope, and the values are the highest on moderate slope ［slope Ⅲ (15°<θ≤25°)］; slope shows a significant (P<0.05) negative correlation with Margalef richness index, and extremely highly significant (P<0.001) and significant positive correlations with Pielou evenness index and Hurlbert index, respectively, with a discontinuous trend of species similarity between slopes. The Margalef richness index and Shannon-Wiener diversity index on east and west slopes are significantly higher than those on northeast and northwest slopes, and aspect shows extremely significant (P<0.01) negative correlations with Margalef richness index, Shannon-Wiener diversity index, and Simpson dominance index; semi-sunny slope combinations show high species similarity, while the northeast slope has relatively low species similarity with the other aspects, and the southwest slope exhibits transitional characteristics. With the decrease of position, the Margalef richness index and Shannon-Wiener diversity index generally increase, and middle and lower slopes have significantly higher values than the upper slope; slope position shows a significant positive correlation with Margalef richness, and an extremely significant negative correlation with Pielou evenness index, with high species similarity between adjacent slope positions. In conclusion, slope, aspect, and position can drive the species diversity pattern of woody plants through the coordinated regulation of hydrothermal distribution, soil nutrients, and habitat heterogeneity. It is recommended to prioritize the protection of diversity core areas including moderate slopes, east and west slopes, and middle and lower slopes, maintain water-heat-nutrient balance and construct ecological corridors, while implementing soil and water conservation and habitat restoration in low-diversity areas such as steep slopes ［slope Ⅳ （25°<θ≤35°）and slope Ⅴ （θ＞35°）］ and northeast and northwest slopes.