Objective To explore the application effect of mobile APP in the rehabilitation nursing of elderly patients with hip arthroplasty. Methods From June 2020 to June 2021, 60 elderly patients who underwent hip arthroplasty in the Department of Orthopaedic Surgery of the Fifth Affiliated Hospital (Zhuhai) of Zunyi Medical University were selected as the research objects. The patients were divided into the intervention group (n=30) and the control group (n=30) according to random number table method. The control group was given routine nursing during the perioperative nursing of minimally invasive total hip arthroplasty. In addition to receiving perioperative routine nursing of hip replacement, the intervention group learned about the patients' rehabilitation through mobile APP and provided rehabilitation exercise guidance according to the patients' own conditions, so as to enhance the patients' confidence in rehabilitation. The hip function recovery, activity recovery, quality of life, complications and compliance with rehabilitation exercise were compared between the two groups. Results There were no significant differences in the Harris score,Barthel index and quality of life score between the two groups before intervention (P＞0.05). After treatment, the Harris scores, Barthel index scores and quality of life scores of the two groups were higher than those before treatment, the differences were statistically significant (P＜0.05). The Harris score, Barthel index and quality of life score of the observation group after treatment were higher than those of the control group, the differences were statistically significant (P＜0.05). The total incidence of complications in the observation group was lower than that in the control group, and the difference was statistically significant (P＜0.05). The total compliance rate of the observation group was higher than that of the control group, and the difference was statistically significant (P＜0.05). Conclusion Mobile APP intervention has a good postoperative nursing effect on elderly patients with hip arthroplasty, it can promote the recovery of patients' hip function, which is worth promoting.