As the core hinterland of the Central Soviet Area and the origin of the main Long March of the Central Red Army, the Gannan area retains a large number of red slogan cartoons. These visual works are the popular propaganda media formed by the Red Army and the Soviet masses in the process of revolutionary practice. Compared with the abstract narrative of written historical materials, the local artistic expression techniques and intuitive and popular picture language of slogan cartoons truly show the actual situation of the struggle in the Soviet area before and after the Long March, and transform the abstract Long March spirit into a visual image that can be intuitively felt and practically understood. This article takes the existing Soviet slogan cartoon remains in Gannan as an analysis sample, combined with the creative practice of representative art creators in the Soviet area, from the context of the work, the logic of expression, the spiritual core, and the contemporary value. The four dimensions are discussed, and the specific analysis of how the slogan cartoon reproduces the spirit of the Long March by means of picture composition, image shaping, and graphic collocation. Based on the current realistic dilemma faced by the inheritance of red culture, this paper explores the activation path that conforms to the law of communication in the new era, and provides practical reference for the concrete dissemination of the Long March spirit and the protective development of red literary and artistic resources in the Soviet area.