Accurate humidity control is important for the electronic operation. Traditional dehumidification has limitations, such as severe condensation, large thermal inertia,  complex equipment. Polymer electrolyte membrane (PEM)-based dehumidification,consisting of five layers of electrolyte, is innovative . It can be powered by low voltage, and has advantages such as compact and accurate. Current research indicated that system performance was still unstable. This paper investigated the durability of PEM-based dehumidifier during long-term operations under various conditions, including the operating temperature, humidity, supplied voltage, etc. Under 3V electric field, the dehumidification rate was reduced by 30% after 280 h. If the voltage increased to 3.8V, although the initial rate increased by 1.5 times, the performance degradation was more serious, which was reduced by 30% within 100 hours. The research will provide a improvement basis for the method in small-space dehumidification.