Film capacitor，as a basic electronic component，is widely used in fields such as energy，military and medical treatment. The metallized film capacitor，compared to foil film capacitor，exhibits excellent features such as small size，low loss and high reliability. However，there are currently some difficulties in thickness measurement，microstructure observation and stress detection for metallized films used in capacitors. In this paper，the research progress and existed specific problems of the metallized films for capacitors in above aspects are summarized and corresponding suggestions are proposed in order to provide theoretical guidance for the development of metallized film capacitors.