Abstract: To elucidate the adaptive mechanisms underlying root morphogenesis and resistance physiology in Angelica sinensis (Oliv.) Diels seedlings in response to terminal damage, a controlled transplant experiment was conducted using the cultivar ‘Mingui No. 2’. Seedlings were subjected to terminal pruning treatments removing 1/2, 1/3, or 1/4 of the apical portion, alongside a non-pruned control (CK). Post-transplant responses were assessed through analysis of root system architecture, biomass allocation, osmotic adjustment compounds, and antioxidative enzyme activity. Results indicated that root cutting shifted lateral root initiation upward and significantly enhanced total root length, total surface area, number of root tips, average root diameter, and biomass. These morphological parameters exhibited a trend of first increasing and then decreasing with aggravation of injury, peaking under the 1/3 pruning treatment. Root cutting significantly increased soluble sugar content, proline content, peroxidase (POD) activity, and membrane lipid peroxidation, with soluble sugar content and POD activity highest under 1/3 treatment, while proline and malondialdehyde (MDA) concentrations were highest under 1/2 treatment. Integrated performance metrics ranked the treatments as 1/3>1/4>1/2>CK. These findings suggest that removing 1/3 of the seedling apex optimally preserves primary root integrity, promotes root formation, enhances osmotic regulation, and activates antioxidant defenses, thereby minimizing transplant-induced stress.