Abstract: Based on Multimodal Discourse Analysis， this paper adopts a combination of quantitative and qualitative research methods to conduct a comparative analysis of the interaction mechanisms between visual and verbal modalities in Chinese and English documentaries. The analysis of the interactive meanings of the visual modalities primarily unfolds from four aspects： contact， social distance， perspective， and modality， while the interpersonal interactive meanings of the verbal modality are analyzed through two dimensions： mood and modality. The research utilizes ELAN software for the segmentation， annotation， retrieval， and statistical analysis of the corpus. The research results show that there are significant differences in the distribution of contact and perspective aspects of the visual modality between Chinese and English documentaries （p＜.05）. Chinese publicity documentary belonged to the weak interaction based on verbal modality and supplemented by verbal modality， while English publicity documentary belonged to the strong interaction with both verbal and visual modality.