This study analyzes Lingnan cultural promotional videos published by official institutions with and without streamers, influencers with and without streamers on social media on the theme of natural scenery and cityscape, historical stories of Lingnan culture, cuisine, folklore, and spring festival customs by the method of multimodal critical discourse analysis. This study also explores the differences in the communication effect of these videos by the method of corpus linguistics. The research results reveal that official videos of natural scenery and cityscapes without streamers use third-person narration and formal lexis, while influencer videos adopt a more personal and emotional style. Official videos with streamers follow a structured, formal approach with guided hosts, while influencer videos are spontaneous and interactive. Unlike official institutions, influencers excel in storytelling about Lingnan culture. In videos of cuisine and customs, official institutions often feature public figures, while influencers engage local chefs or folk practitioners in casual Cantonese conversations. Official videos use scripted narration, while influencer videos focus on entertainment, creating an immersive, dynamic experience. This study not only contributes to the better dissemination of Lingnan culture but also provides a foundation for the construction of the “Cultural Bay Area” image, creating a harmonious and friendly cultural ecosystem and public opinion environment.