To investigate the clinical effect of anterolateral thigh free flap in the treatment of skin soft tissue defect of foot. Methods A total of 40 patients with skin soft tissue defect of foot admitted to Bozhou District People's Hospital, Zunyi City from January 2021 to May 2023 were selected and divided into control group and observation group according to different surgical methods, with 20 patients in each group. The control group was repaired with traditional pedicle flap, and the observation group was repaired with anterolateral thigh free flap. The clinical indexes, flap survival rate and foot function recovery were compared between the two groups. Results The intraoperative blood loss in the observation group was less than that in the control group, the operation time and hospitalization time were shorter than those in the control group, and the appearance satisfaction was higher than that in the control group (P <0.05). The survival rate of the flap in the observation group was higher than that in the control group (P <0.05). The AOFAS scores of each dimension in the observation group were higher than those in the control group (P <0.05). Conclusion In the treatment of skin soft tissue defect of foot, the anterolateral thigh free flap repair is effective, which can effectively reduce the amount of intraoperative blood loss, shorten the operation time and hospitalization time, improve the appearance satisfaction and flap survival rate, and promote the recovery of foot function.