From the perspective of international Chinese communication, this study investigates the optimization of English translation for Chinese short video content. Using a case study approach, six representative short video cases from TikTok and YouTube were selected, covering cultural, lifestyle, humor, and live-streaming content. Through sentence-by-sentence comparison and qualitative analysis, the study identifies five major categories of translation problems, such as improper handling of culture-specific elements, clumsy translation of colloquial and internet slang, loss of humor and double entendre, excessive subtitle length, and conflicts between verbal and visual information. In response, the study proposes corresponding optimization strategies, including retaining core cultural terms with concise explanations, pursuing pragmatic equivalence in colloquial translation, reconstructing humor functionally rather than literally, compressing subtitle length to suit short-video reading speed, and utilizing multimodal compensation strategies. The findings demonstrate that short videos, due to their fragmented, colloquial, and multimodal nature, impose new demands on traditional translation approaches. This study not only enriches research on audio-visual translation (AVT) within the context of short videos but also provides practical guidance for translators and content creators seeking to improve the international communication effectiveness of Chinese short video content.