Knowledge-centered translatology posits that translation is a process of globalization of local knowledge, which centers around knowledge construction. Subtitle translation of documentaries exemplifies this interaction and transfer between local and global knowledge. Guided by the principles of truth, virtue and beauty, this paper examines the subtitle translation of the documentary Harmony Between Humanity and Nature and explores the inherent mechanisms of subtitle translation in this work. By analyzing representative cases, we find that some translations of the documentary’s subtitles adhere to the principles of truth, virtue and beauty. Therefore, these translations convey authentic meanings, take into consideration the target audience, and meet the aesthetic standards of the target language. However, others do not follow these principles, which hinders the documentary’s international reach.