Objective To analyze the risk factors of posterior capsular rupture (PCR) in phacoemulsification. Methods A total of 5 415 patients (5 743 eyes) who underwent phacoemulsification combined with intraocular lens implantation in Shanghai Fengxian District Hospital of Traditional Chinese Medicine from January 2011 to December 2017 were selected in this retrospective study. A total of 120 eyes from 105 patients with intraoperative lens PCR were assigned to observation group, and 480 eyes from 452 patients were randomly selected as control group. The data was compared between 2 groups, including general information (gender, age), systemic risk factors (hypertension, diabetes, cardiovascular disease, history of glucocorticoid use, smoking, drinking), basic ophthalmic information and risk factors (vision, intraocular pressure, history of glaucoma, history of high myopia, history of keratopathy, history of uveitis, cataract type, vitreous hemorrhage, history of vitreous surgery), and cataract nucleus hardness. Results The ratios of eyes with preoperative visual acuity<20/200 (89.2%[107/120] vs 58.1%[279/480]), vitreous hemorrhage (10.8%[13/120] vs 2.3%[11/480]), and vitreous operation history (20.8%[25/120] vs 4.8%[23/480]) in observation group were significantly higher than those in control group (P<0.05). The lens nucleus hardness was classified in 111 eyes in the observation group and 459 eyes in the control group. There was significant difference in the hardness of lens nucleus between the observation group (9 eyes[8.1%] of grade Ⅰ, 11 eyes[9.9%] of grade Ⅱ, 10 eyes[9.0%] of grade Ⅲ, 46 eyes[41.4%] of grade Ⅳ and 35 eyes[31.5%] of grade Ⅴ) and the control group (88 eyes[19.2%] of grade Ⅰ, 82 eyes[17.9%] of grade Ⅱ, 109 eyes[23.7%] of grade Ⅲ, 97 eyes[21.1%] of grade Ⅳ and 83 eyes[18.1%] of grade Ⅴ) (P<0.05). The visual acuity of logMAR was restored from 2.11±0.98 to 1.07±0.44 in the observation group (P<0.05), and from 1.37±0.90 to 0.72±0.37 in the control group (P<0.05). LogMAR visual acuity of the patients before and after operation was poor in the observation group versus the control group (both P< 0.05). Conclusion Preoperative visual acuity<20/200, vitreous hemorrhage, history of vitreous surgery and lens nucleus hardness classification are the risk factors of PCR in phacoemulsification.