Objective To investigate the effects of different doses of Esketamine + Dexmedetomidine on postoperative sleep quality and cognitive function of patients with hip fracture. Methods From July 2023 toJuly 2024, 90 elderly patients undergoing hip fracture surgery in the Clinical College of Henan University of Science and Technology were randomly divided into N group, L group and H group, with 30 patients in each group. N group was the blank control group, and dexmedetomidine was infused during the operation as the control group. Group L was low-dose Esketamine group, and dexmedetomidine combined with low-dose Esketamine was infused during operation. Group H was the high-dose Esketamine group, and dexmedetomidine combined with high-dose Esketamine was infused during the operation. The hemodynamic changes, postoperative sedation pain and postoperative sleep were compared among the three groups. Results The hemodynamics of patients in group L and group H were more stable in PACU period of operation, and the sedation scores (Richmond Agitation and Sedation Scale, RASS) was significantly higher than that of group L and group H (P<0.05), while the VAS score was significantly higher than that of group L and group H (P<0.05), and the VAS score of group L was significantly lower than that of group H (P<0.05). At the same time, the subjective and Objective sleep quality of the three groups were significantly improved after operation, and the improvement effect of L group was the most significant. Conclusions Esketamine + Dexmedetomidine is used in the anesthesia of elderly patients with hip fracture, and the effect of low dose Esketamine is better.