【Objective】 To investigate the predictive value of non-invasive parameters in assessing detrusor function in patients with benign prostatic hyperplasia (BPH). 【Methods】 Clinical data of 384 BPH patients to undergo surgery were enrolled and retrospectively analyzed. The patients’ age and medical history time (MHT) were recorded. The free urinary flow rate was measured and maximum flow rate (Qmax) was recorded. Post-void residual (PVR) and voiding volume (VV) were measured with Bladder Scan, and bladder voiding efficiency (BVE) was calculated. Parameters including detrusor pressure (Pdet@Qmax) and Watts factor (WFmax) were collected in invasive urodynamic examination. Patients were grouped as detrusor underactivity (DU) group and non detrusor underactivity (NDU) group according to the results of WFmax, and the factors influencing detrusor function were analyzed with Logistic regression. The optimal cut-off values were confirmed with receiver operating characteristic (ROC) curve. 【Results】 Significant differences were observed in patients’ age, MHT, Qmax, PVR, BVE, Pdet@Qmax between the DU and NDU groups. Logistic regression showed that the overall prediction accuracy was higher when MHT, Qmax and BVE were included. The model prediction formula was Y=6.020-0.451XMHT+0.554XQmax-0.074XBVE. ROC curve showed when age ≥70.5 years and MHT≥ 7.5 years, there was a greater possibility of DU. When Qmax ≥5.7 mL/s and BVE ≥75.5%, the contractile function of detrusor was normal. Model prediction formula Y≥0.72 showed that detrusor contractility was normal. 【Conclusion】 Age, MHT, Qmax and BVE have certain predictive value for assessing detrusor function in BPH patients.