Objective To investigate the effect of surgical timing of parathyroidectomy on renal transplant function in renal transplant patients with persistent hyperparathyroidism.Methods The data of all patients who underwent allogeneic kidney transplantation combined with parathyroidectomy (PTX) combined with forearm transplantation in West China Hospital of Sichuan University and the Air Force Hospital of the Western Theater Command from January 2000 to August 2019 were collected. The timing of forearm transplantation (0-12 months, 12-24 months, 24-36 months, and more than 36 months) in each group of patients with albumin, serum creatinine, glomerular filtration rate, parathyroid hormone, serum calcium, serum phosphorus and the distribution of alkaline phosphatase. Results At 1 week, 1 month, 3 months and 1 year after operation, there was no statistical difference in serum calcium among the groups; at 6 months after operation, the blood calcium in the 0-12 month group was the lowest, and the >36 month group was the highest. At each time point after PTX combined with forearm transplantation, the serum phosphorus in the 12-24 month group was the lowest, except for 1 month after the operation, the differences in the other time points were statistically significant; while in the >36 month group, the serum phosphorus level was the highest at 1 week, 3 months, 6 months and 12 months after PTX combined with forearm transplantation. The alkaline phosphatase level of the >36 month group was significantly lower than that of the other groups before and after PTX combined with forearm transplantation, while in the 0-12 month group, the 12-24 month group and the 24-36 month group the levels of alkaline phosphatase at each time point after PTX combined with forearm transplantation were similar. At each time point after PTX combined with forearm transplantation, the serum albumin of each group was also within the normal range, and there was no statistical difference between the groups. At each time point after PTX combined with forearm transplantation, the glomerular filtration rate of the 12-24 month group was the highest, and was significantly higher than that of the other groups, with a statistical difference. Conclusion The optimal timing of PTX combined forearm transplantation for Kidney transplantation with persistent hyperparathyroidism patients is 12-24 months after transplantation, which has the least impact on the function of the transplanted kidney