Metaphors are a core category of cognitive linguistics and an important mode of human thinking. They concretize abstract concepts through cross-domain mapping and build a bridge between cognition and understanding in verbal communication and interpersonal communication. Metaphor research has shifted from a pure linguistic perspective to multidisciplinary and multimodal research. However, there has yet been no systematic review of how the brain processes the differentiation and integration mechanism of verbal and non-verbal modal metaphorical information, as well as the main influencing factors. In particular, a weak area in current research is how special groups achieve compensation of metaphorical understanding through neuroplasticity. This review systematically describes the relevant achievements in cognitive neuroscience in recent years, with the aim of revealing the main influencing factors of multimodal metaphor processing and the process of neural differentiation and cross-modal integration. This review also focuses on the compensatory mechanisms in autism, aphasia, and deafness, and describes how they achieve effective metaphorical understanding through the reconstruction of neuroplasticity. Moreover, it provides an integrated perspective for understanding the neural basis of metaphorical cognition, as well as a theoretical basis and practical guidance for advancing multimodal metaphor research and applications in rehabilitation. Future research should combine temporal neurodynamic technology with ecological interventions designed to further promote advancement in this field.