This study aimed at compare the safety and efficacy between 100 U suburothelial injection and combined 50 U suburothelial and 50 U urethral sphincter injection of BoNT-A in patients with detrusor overactivity and inadequate contractility (DHIC). A total of 60 patients with DHIC will be enrolled and randomly allocated to each group and treated with either regimen. The safety and efficacy will be assessed by the Patient's Perception of Bladder Condition (PPBC) at different time points after injection. The results of this study may provide valuable evidence for the rational treatment regimen for patients with DHIC.