AIM: To investigate whether Wild Field Imaging System (WFIS SW-8000), 25G endoilluminator, and intraoperative optical coherence tomography (iOCT) can perform real-time screening and diagnosing in patients with suspicious diabetic retinopathy (DR) during phacoemulsification, especially in cases of white cataract. METHODS: A cross-sectional study was carried out. A total of 204 dense diabetic cataractous eyes of 204 patients with suspected DR treated from April 2020 to March 2021 were included. Phacoemulsification combined with intraocular lens implantation was performed. Following the removal of the lens opacity, the 25G endo-illuminator, fundus photography, and iOCT were performed successively. Optical coherence tomography (OCT) and/or fundus fluorescein angiography (FFA) were used to verify the fundus findings postoperatively. Intraoperative and postoperative results were compared to verify the accuracy of intraoperative diagnosis in each group. RESULTS: Intraoperative and postoperative examinations revealed 58 and 62 eyes with DR, respectively (positive rate, 28.43% and 30.39%, respectively). During the phacoemulsification, WFIS SW-8000 detected 44 eyes with DR (the detection rate, 70.97%); 25G endo-illuminator found 56 eyes with DR (the detection rate, 90.32%); iOCT found 46 eyes with DR (the detection rate, 74.19%); and 58 eyes with DR were found by combining the three methods (the detection rate, 93.55%). There were statistically significant differences in the diagnostic sensitivity for DR among the methods (χ2=16.36, P=0.001). CONCLUSION: WFIS SW-8000, 25G endo-illuminator, iOCT, and especially their combination can be used to inspect the fundus and detect DR intraoperatively; they are helpful for the timely diagnosis and treatment of DR in patients with dense cataract.