Objective: To analyze the relationship between corneal B/F ratio and postoperative refractive error in age-related cataract patients, and to explore the impact of B/F ratio on the accuracy of intraocular lens power calculation. Methods: A total of 197 age-related cataract patients (197 eyes) who were treated in the cataract center of our hospital from March 2019 to November 2019 and were going to undergo monocular cataract surgery were selected. The biological parameters of the anterior segment were measured by Pentacam anterior segment analyzer before surgery, and the patients were divided into three groups (25% below the B/F ratio, 25%~75%, and 25% below the B/F ratio) with the lower limit and the upper limit of 25%. Three months after surgery, the postoperative refractive state of patients was evaluated by automatic computerized refractometer, and the postoperative refractive error (PE) was calculated, and the percentage differences of mean refractive error (ME), mean absolute error (MAE), median absolute error (MedAE) and refractive error in the range of ±0.25, ±0.50, ±0.75, ±1.00 and < ±1.00D were evaluated. Results: The B/F ratio was moderately correlated with postoperative refractive error in age-related cataract patients (r= ?0.445, P < 0.001). With the increase of B/F ratio, the refractive state of patients shifted from hyperopia to myopia after surgery, and the MAE and MedAE were 0.55 D and 0.46 D respectively in 3 months after surgery. The percentages of refractive error in the range of ±0.25, ±0.50, ±0.75, ±1.00 and < ±1.00 D were 29.4%, 52.8%, 71.6%, 87.6% and 12.7%, respectively. After adjusting the corneal curvature according to the B/F ratio of the population based on our previous study, MAE and MedAE were 0.51 D and 0.43 D, respectively, which were lower than those before correction (P< 0.05). Conclusions: There is a correlation between B/F ratio and postoperative refractive error in age-related cataract patients. As the B/F ratio increased, the refractive state of the patient gradually drifted from farsightedness to myopia after cataract surgery, and the more the B/F ratio deviated from the normal average, the greater the absolute value of the patient's refractive error.