AIM: To investigate the changes of corneal endothelial cells and ocular surface after phacoemulsification for age-related cataract(ARC)patients with diabetes mellitus. METHODS: Retrospective case study. A total of 190 cataract patients with diabetes mellitus who received phacoemulsification combined with IOL implantation in 190 eyes admitted to our hospital from January 2017 to January 2019 were selected. In addition, 230 ARC patients without diabetes who underwent phacoemulsification and intraocular lens implantation at the same time were selected as the control group. Ocular surface disease index(OSDI)score, tear film rupture time(BUT), basal tear secretion test(S I t), corneal endothelial cell density and coefficient of variation were compared between the two groups.RESULTS: There was no significant difference in preoperative OSDI score, BUT, S I t, corneal endothelial cell density and coefficient of variation between the two groups(P>0.05). In the observation group, OSDI scores were significantly increased 1wk, 1mo and 3mo after surgery compared with those before surgery, with statistically significant differences(all P<0.01). The OSDI scores of patients in the control group increased significantly one week and one month after the operation compared with those before the operation, with statistically significant differences(all P<0.01). The OSDI scores in the observation group at each time point after the operation were higher than those in the control group, with statistically significant differences(all P<0.05). One week after surgery, 1mo after surgery, BUT and S I t in the two groups decreased significantly compared with that before surgery(P<0.05), and the difference was not statistically significant compared with that before surgery 3mo after surgery. In addition, compared with BUT between the two groups, the observation group had a lower tear film stabilization time and a more significant decrease(P<0.05). The corneal endothelial cell density in the two groups decreased significantly 1wk, 1mo and 3mo after surgery compared with that before surgery(P<0.05). The variation coefficient of corneal endothelial cells in the two groups was statistically significant 1wk after the operation and 1mo after the operation compared with that before the treatment(P<0.05). The variation coefficient of corneal endothelial cells in the observation group was more significant than that in the control group(P<0.05).CONCLUSION: Cataract patients with diabetes surgery tolerance is low, the corneal endothelial cell density and the central corneal thickness and corneal appears before tear secretion with stability and foundation treatment have significant changes, and its characteristic is cataract patients without diabetes more apparent, clinical intraoperative and postoperative corneal endothelial protection should be strengthened, and the surface of the eye protection ability of the organization.