Objective: To investigate the predictive value of preoperative albumin (ALB) level on postoperative severe hypocalcemia (SH) in patients with secondary hyperparathyroidism (SHPT). Methods: The data of 90 patients with SHPT treated in the Department of Thyroid Gland and Breast Surgery of Lu’an Hospital of Traditional Chinese Medicine from January 2019 to June 2021 were analyzed retrospectively. According to the blood calcium monitoring after parathyroidectomy (PTX), they were divided into an SH group (blood calcium level ≤1.8 mmol/L, n=29) and a control group (blood calcium level >1.8 mmol/L, n=61). The perioperative related data of the 2 groups were compared. The relationship between preoperative ALB level and the occurrence of SH after PTX in SHPT patients was analyzed by multivariate logistic regression model and receiver operating characteristic curve. Results: The levels of alkaline phosphatase (ALP), ALB, and the proportion of parathyroid resection ≥4 in SH group were significantly higher than those in the control group (P<0.05). Preoperative ALP (OR =1.442, 95%CI: 1.334–5.881), preoperative ALB (OR =1.391, 95%CI: 1.168–3.159) and the number of parathyroidectomy ≥4 (OR =2.248, 95%CI: 1.211–7.352) were independent risk factors for SH after PTX (P<0.05). The area under curve (AUC) predicted by preoperative ALB was 0.714 (95%CI: 0.577–0.850), and ACU predicted by preoperative ALP was 0.729 (95%CI: 0.586–0.872), without significant difference between the 2 groups (P>0.05). Conclusion: Preoperative ALB level is a risk factor for SH after PTX in SHPT patients. It has reference value for early screening high-risk groups of SH and predicting the occurrence of SH.