Abstract: Based on an aramid polymer prepared, the modified aramid dope is prepared through a combination of covalent crosslinking and non-covalent crosslinking. By adjusting the amounts of a crosslinking agent and a polar polymer, an aramid film is obtained that meets the following requirements simultaneously: superior heat resistance and mechanical strength, high toughness, a simple preparation process, high stretchability, and resistance to breakage. Furthermore, the aramid film can be directly laminated with aramid paper without use of an adhesive, so that a flexible composite material in compliance with insulation class F or H is prepared through direct lamination. This application is widely applicable to motors, generators, transformers, adhesive tape, and other fields.