This study investigates the effectiveness of multimodal teaching methods in college English writing courses, contrasting these innovative approaches with traditional teaching methods. By integrating multimodal knowledge mapping into an English teaching platform, we aimed to enrich students’ learning experiences and enhance their writing skills. A comparative analysis involving two classes—one employing the traditional teaching method and the other utilizing the multimodal approach—revealed significant improvements in the multimodal group. Students in the experimental class demonstrated heightened interest, improved attitudes and cognition towards English writing, and their average writing scores increased by 2.68 points, from 12.66 to 15.34. In contrast, the control group showed no significant score changes. Our findings underscore the multimodal teaching method’s capacity to effectively elevate students’ English writing abilities, marking a successful adaptation to modern educational demands.