The development and application demands of polyaniline (PANI) electrochromic films are introduced. Among all the electrochromic film materials, flexible material is a key research direction. The working mechanism of typical polyaniline materials is analyzed. Based on printing electronic technology, the experimental researches on the preparation technology of the flexible electrochromic film are performed. Polyaniline solution proportion experiment, performance testing process, and other researches are carried out, which provides the best ratio for polyaniline electronic printing ink preparation. Through electronic silk screen printing tests and the improvement of the chemistry formulation of electronic printing ink, the key technology of the flexible polyaniline electrochromic film production based on printing electronic technology is solved.