The Third Plenary Session of the 20th Central Committee of the Communist Party of China emphasized the need to build a more effective international communication system, within which the dissemination of China’s national image plays a crucial role. As a vital carrier of cultural communication and a key representation of comprehensive national strength, national image has, in the context of globalization, become an essential component of a country’s global influence. Among cultural mediums, films—particularly new mainstream films —have consistently served as a powerful tool for constructing and disseminating China’s national image.This study argues that, since the advent of the new era, Chinese films, especially new mainstream films, have become an important window through which China’s national image is communicated internationally. These films portray, across multiple dimensions and levels, an open and inclusive image of a major country, a people-centered political image, a powerful military image, a diligent social image, and a confident and self-reliant national image.Nevertheless, challenges remain in the international communication of new mainstream films, including significant cultural discounting, formidable barriers within mainstream markets, a relatively narrow range of film genres, and a lack of flexibility in expressive techniques. To overcome these obstacles, new mainstream films must adhere to the guidance of Xi Jinping Thought on Culture, fully implement the spirit of the Third Plenary Session of the 20th Central Committee of the Communist Party of China, construct a Chinese narrative system to enhance empathy in international communication; optimize communication methods and strategies to boost affinity in international communication; expand foreign exchange and cooperation to strengthen competitiveness in international communication; advance the construction of support systems to improve organizational capacity in international communication. The active construction of a multi-channel and multi-level international communication system will comprehensively enhance the effectiveness of international communication for China’s national image.