Objective To investigate the effect of cognitive frailty before operation on postoperative joint function in elderly patients with hip fracture at different periods. Methods A total of 206 elderly patients with hip fracture were selected by convenient sampling, and surveyed with the general data questionnaire, the FRAIL scale, the Mini-Mental Status Examination and the Functional Recovery Scale.Generalized estimation equation (GEE) models were used to probe the influencing factors of joint functions mea-sured at varied timepoints within 3 months postoperatively. Results The prevalence of pre-operative cognitive frailty in elderly patients with hip fracture was 38.3%.Postoperative joint function recovery scores improved overtime in both frail and non-frail groups.There were significant differences in joint function recovery scores between the two groups at all timepoints （all P＜0.05）.Pre-operative cognitive frailty scores were negatively correlated with joint function recovery scores at different timepoints postope-ratively （all P＜0.05）.GEE analysis showed that age, the Charlson Comorbidity Index (CCI) score and the American Society of Anesthesiology physical status classification score, serum sodium level, albumin level, time into rehabilitation exercise, postoperative time and cognitive frailty were influencing factors of postoperative joint function recovery scores （all P＜0.05）. Conclusion The prevalence of preoperative cognitive frailty among elderly patients with hip fracture is high, which may have negative influence on recovery process of postoperative joint function.Attention should be paid to assessment of cognitive frailty status before operation, which could provide a basis for frailty prevention and intervention.