Urinary leakage volume is a crucial indicator reflecting the condition of patients with urinary incontinence. Currently, there are limited smart diapers capable of continuous dynamic detection of urinary volume. This study developed two types of urinary volume sensors based on resistance and capacitance, integrating them with traditional diapers for evaluating the severity of urinary leakage: mild leakage: 0-5mL; moderate leakage: 6-12mL; severe leakage: above 12mL. Three patterns of resistance-based urinary volume sensors were designed. The results showed that Pattern A could accurately determine the level of urinary volume. Additionally, three electrode distances of capacitance-based urinary volume sensors were designed. The results demonstrated that the sensor with a 1cm electrode spacing could detect the urinary volume range, indicating 1mL per drop with a capacitance increase of approximately 1.5-1.8pF. The error per drop was around ± 0.5mL. This study validated the feasibility of smart flexible textile sensors in urinary volume detection, providing a potential solution for better assessing and managing the condition of patients with urinary incontinence.