Objective To explore the clinical effect of ultrasound-guided iliac fascia block combined with hypobaric spinal anesthesia in elderly hip surgery. Methods A total of 300 elderly patients with hip joint diseases who were treated in our hospital from January 2019 to December 2022 were selected as study subjects. They were divided into two groups according to their surgical treatment time, 150 patients in each group. Among them, patients who were treated from January 2019 to December 2020 served as the control group, and received hypobaric spinal anesthesia; those who were treated from January 2021 to December 2022 served as the study group, and received ultrasound-guided iliac fascia block combined with hypobaric spinal anesthesia. The anesthesia effect and related complications were compared between the two groups. Results Comparative analysis results showed that the effective time and successful time of sensory block and motor block in the study group were shorter than those in the control group （P<0.05）. The total incidence of related complications in the study group during the whole treatment period was 3.34%, lower than 9.34% in the control group （P<0.05）. Conclusion The active implementation of ultrasound-guided iliac fascia block combined with hypobaric spinal anesthesia in the treatment of hip joint surgery in elderly patients generates an ideal anesthetic effect and reduces the occurrence of related complications in patients.