Abstract: 【Objective】 To study the effects of subsoiling depth on the plant morphological structure and biomass accumulation of sugar beet during the growth period in southern Xinjiang, so as to provide a basis for the construction of reasonable tillage layer of sugar beet field in southern Xinjiang. 【Method】 A field randomized block design was used in this study and four subsoiling treatments were set: 35 cm (S₃₅), 45 cm (S₄₅) and 55 cm (S₅₅) to study the effects of different subsoiling depths on plant morphological structure characteristics, biomass accumulation of various organs, and the correlation between morphological structure characteristics of leaves and petioles and morphological indexes of root tubers. 【Results】 The leaf length, leaf width, leaf fresh weight, petiole length, petiole diameter and petiole fresh weight increased first and then decreased with the increase of leaf order during the growth period of beet leaf cluster, among which, the maximum value of L₅ leaf appeared, which could be used as functional leaf and the subsoiling depth of 55 cm promoted the growth of long-term functional leaf and petiole of beet leaf cluster. Compared with CK, the root length, root diameter, root girth and fresh weight of root increased by 25.93%, 25.59%, 30.15% and 19.19%, respectively (P< 0.05), and the ratio of total fresh weight per plant and leaf fresh weight increased by 29.99% and 9.96%, respectively, while the ratio of root fresh weight and root shoot ratio decreased by 8.35% and 14.29%. 【Conclusion】 Subsoiling depth of 55 cm in southern Xinjiang can effectively promote the growth of sugar beet leaves.