Objective To make biomechanical analysis on soft tissues in the formation of postburn claw hand deformity and during its two traction orthodontic treatments. Methods The hand model containing skin and scar was established, and the scar contracture-tendon and ligament contracture-scar excision with skin grafting- traction orthodontic treatment process for postburn claw hand deformity was simulated. Biomechanical analysis on relevant soft tissues was performed, and the advantages and disadvantages of the two traction modes were compared. Results The associated flexors and extensors were stretched when scar contracture occurred. The dorsolateral ligaments at the metacarpophalangeal ( MCP) joints were relaxed and most of the lateral collateral ligaments were tensed. After surgical treatment, the deformity was largely relieved. Tension or laxity of the tendons was reduced. The tensed lateral collateral ligaments were relaxed and the contracted dorsolateral ligaments were stretched. Traction orthodontic treatment was gainful for scar removal surgery. For postburn claw hand deformity, the treatment protocol of dynamic traction applied directly after scar release set up in this study was safe and effective, and had a better promotion effect on tendon elongation. In terms of traction effect, the elongated traction method showed more advantages than the antagonistic traction. Conclusions The research results may provide references for clinical interventions and prognosis improvement of patients.