In the context of the digital age, this paper investigates the intermedial transformation of painting language, revealing the development and boundary expansion of traditional painting language under the influence of digital media. The research focuses on the transformations triggered by the intervention of digital technology in traditional painting and the new characteristics that emerge post-digitalization. By analyzing the historical evolution and current status of painting language and selecting representative artistic practices, the study captures the phenomenon of painting language updating through digital intermedial transformation. Combining intermedial art theory and visual analysis methods, it further explores the specific methods and internal logic of traditional painting language’s intermedial transformation in the digital age. The research summarizes the innovative paths, aesthetic values, and impacts on the ontology of painting language in the fusion of traditional painting and digital media. Based on these insights, the personal practice of painting language intermedial transformation was completed. The results highlight three primary strategies for this transformation: technological innovation, data generation, and immersive interaction, and reflect on the boundaries of painting language ontology within these strategies. Finally, the paper summarizes the research findings, discusses the limitations, and suggests directions for future research. The innovation of this paper lies in applying intermedial art theory as a method to analyze the overall transformation of painting language in the digital age, providing a new perspective for understanding and evaluating the shifts in artistic practice under digital media.