Objective To compare the efficacy and safety of forearm subcutaneous and brachioradialis parathyroid autotransplantation (PA) in the prevention of hypoparathyroidism (HypoPT) after thyroidectomy. Methods A total of 99 patients who underwent thyroidectomy combined with forearm PA for the first time in Fushun Central Hospital from May 2022 to August 2023 were selected. According to their treatment intention, patients were divided into exposed group (forearm subcutaneous PA, 49 patients) and control group (brachioradialis PA, 50 patients). The differences of general clinical data and postoperative indexes between two groups were compared, and the influencing factors of parathyroid autograft one month after surgery were analyzed by multivariate Logistic regression. Results The blood calcium level in exposed group was significantly higher than that in control group at one day and three days after surgery (P<0.05). One month after surgery, the forearm parathyroid autograft survival rate in exposed group was significantly higher than that in control group (P=0.029). The incidence of postoperative perioral, fingertip numbness and local congestion in exposed group was significantly lower than that in control group (P<0.05). There was no significant difference in occurrence of temporary HypoPT between two groups (P>0.05). Multivariate Logistic regression analysis showed that gender and implant site were the influencing factors for forearm parathyroid autograft survival one month after surgery (P<0.05). Conclusion Forearm subcutaneous PA is a safe, simple and effective way to prevent HypoPT after thyroidectomy, which is worthy of clinical promotion and application.