Designing new medical devices with advanced humidity sensors is of great significance for patients with incontinence-associated dermatitis (IAD). The primary goal of this study is to test the humidity-sensing mattress system for patients with IAD in clinical settings. The design of the mattress is set at 203 cm, with 10 × 3 sensors, dimensions of 19 × 32 cm, and a weighted bearing of 200 kg. The main sensors consist of a humidity-sensing film, a thin-film electrode (6 × 0.1 mm), and a glass substrate (500 nm). The sensitivity of the test mattress system showed that the resistance-humidity sensor was at a temperature of 35 °C (V0= 30 V,V0= 350 mV), with slope at 1.13 V/fF,f= 1 MHz, 20–90% RH, and a response time of 20 s at 2μm. In addition, the humidity sensor reached 90% RH, with a response time of less than 10 s, a magnitude of 107–104Ω, 1 mol%,CrO1.5, and FO1.5, respectively. This design is not only a simple, low-cost medical sensing device, but also opens a new pathway for developing humidity-sensing mattresses in the field of flexible sensors, wearable medical diagnostic devices, and health detection.