Objective:To investigate the effects of dexmedetomidine combined with propofol on cognitive function, hemodynamics and diaphragm movement in elderly patients undergoing painless gastroenteroscopy.Methods:The clinical data of 82 patients who underwent painless gastroenteroscopy in Fuyang Minsheng Hospital from April 2021 to November 2022 were retrospectively collected, and they were divided into the control group and the observation group by anesthesia induction method, each group with 41 cases. The control group was anesthetized with propofol, and the observation group was anesthetized with dexmedetomidine and propofol. The recovery time, orientation recovery time and satisfaction of the two groups were compared; the cognitive function before anesthesia, 1, 12 h after anesthesia and 1, 7 d after anesthesia were compared; the changes of hemodynamics and diaphragm movement before anesthesia induction (T 0), 5 min after anesthesia induction (T 1) and at awakening (T 2) and adverse reactions were compared. Results:The recovery time, orientation recovery time in the observation group were shorter than those in the control group: (9.87 ± 1.52) min vs. (11.92 ± 1.74) min, (15.87 ± 2.31) min vs.(18.79 ± 2.54) min; the dosage of propofol was less than that in the control group: (200.21 ± 50.46) mg vs. (300.23 ± 60.29) mg; the satisfaction scores was higher than that in the control group: (9.54 ± 0.32) scores vs. (8.81 ± 0.47) scores, there were statistical differences ( P<0.05). The scores of Mini-Mental State Examination (MMSE) at 1 h after anesthesia and 12 h after anesthesia in the observation group were higher than those in the control group: (23.12 ± 1.86) scores vs. (20.31 ± 1.65) scores, (26.21 ± 1.43) scores vs. (24.12 ± 1.57) scores, there were statistical differences ( P<0.05). The scores of MMSE at 1, 7 d after anesthesia had no statistical differences between the two groups ( P>0.05). The levels of mean arterial pressure (MAP) and heart rate (HR) at T 1 and T 2 were decreased and the levels of MAP and HR at T 1 and T 2 in the observation group were higher than those in the control group: (76.48 ± 4.01) mmHg (1 mmHg = 0.133 kPa) vs. (72.31 ± 3.26) mmHg, (82.31 ± 3.27) mmHg vs. (77.97 ± 3.64) mmHg; (78.72 ± 2.17) bpm vs. (76.23 ± 2.35) bpm, (82.19 ± 3.08) bpm vs. (79.63 ± 2.56) bpm, there were statistical differences( P<0.05). The diaphragm thickness fraction (DTF) and diaphragmatic motion amplitude (DM) at T 1 and T 2 were decreased and the levels of DTF and DM at T 1 and T 2 in the observation group were higher than those in the control group: 0.21 ± 0.02 vs. 0.17 ± 0.03, 0.26 ± 0.03 vs. (0.22 ± 0.04); (15.67 ± 0.81) mm vs. (14.21 ± 0.77) mm, (16.72 ± 0.68) mm vs. (15.46 ± 0.82) mm, there were statistical differences ( P<0.05). The adverse reactions in the two groups had no significant difference ( P>0.05). Conclusions:The combination of dexmedetomidine and propofol has little effect on cognitive function, hemodynamics and diaphragm movement in elderly patients undergoing painless gastroenteroscopy, which can accelerate the recovery of patients and improve patient satisfaction.