Abstract: To clarify the plant morphological characteristics suitable for mechanical topping, this study analyzed the plant structure traits and mechanical topping performance of 14 major flue-cured tobacco varieties in China. The correlation between topping performance and plant morphological traits was examined to identify tobacco varieties suitable for mechanical topping. The results indicated that plant height, coefficient of variation in plant height, stem circumference, number of leaves, flower bud height, upper leaf length, and the angle between the upper leaves and the stem were closely associated with topping performance. These indicators could effectively predict topping performance through logistic regression analysis. For optimal mechanical topping, the flowering period should be relatively concentrated (from bud emergence to full bloom ≤ 7 days), and the plant morphological traits should meet the following criteria: plant height ranging from 140 to 165 cm, coefficient of variation in plant height less than 5%, stem circumference between 8.6 and 11.5 cm, number of leaves between 27 and 30, flower bud height greater than 39.8 cm, upper leaf length less than 61.8 cm, and the angles between the upper leaves and the stem and the leaf droop angle greater than 29.9° and 39.5°, respectively. Among the tested varieties, Zhongyan 301 and Zhongyan 101 varieties exhibited the best topping performance with the topping machine employed in this study.