Electrolytic capacitor paper, also known as capacitor diaphragm paper, acts as isolation and insulation between anode and cathode aluminum foil of electrolytic capacitor. The better the quality of electrolytic capacitor paper is, the better it can meet the requirements of capacitor voltage resistance, electrical impedance and small loss, which determines the life of photovoltaic inverter for the reliability of its components. While semiconductor components typically achieve this level of reliability, it can be a challenge for passive components, especially electrolytic capacitors. The reliability of electrolytic capacitor has become one of the keys to improve the reliability of photovoltaic inverter.