In nature, plants have various functional traits, that cooperate or complement each other to aid in their adaptation to complex environments. Therefore, the complex relationships between various functional traits can reflect the adaptive strategies of plant survival, growth, and reproduction and their response to the environment to a large extent. At present, most research is limited to simple relationships between single or a few specific traits, and multidimensional approaches and quantitative methods are still very rare, limiting our comprehensive understanding of plant adaptation mechanisms. Traditional analysis methods, such as correlation analysis, principal component analysis, path analysis, and structural equation model, may not always fully elucidate the complex relationships between various functional traits, although they have their advantages. In bridging this gap, researchers have introduced innovative concepts like multidimensional network analysis and plant trait networks (PTNs) or plant functional trait networks, which contribute to a new research framework for studying complex biological systems. PTNs are defined as multidimensional networks of various functional traits, each having its overall characteristics (or node characteristics) that depict the complex relationships among diverse traits, as well as the response and adaptation strategies of individual plants, functional groups, and communities to environmental change and disturbance. Based on this, five important network parameters and four core node parameters of PTNs are defined in terms of their physiological and ecological significance. Theoretically, PTNs have the potential to capture and visualize the relationships among plant traits in multiple dimensions, providing a novel perspective on understanding plant responses and adaptation strategies to environmental or resource changes. By introducing the concept, theory, parameters, and methods of PTNs, the scientific nature and adaptability of PTNs are discussed herein based on examples from forest transects in eastern China and global-scale leaf functional traits data. Overall, the theoretical framework of PTNs provides a new approach for exploring the multidimensional adaptation mechanisms of plants at different scales and their responses to future global changes.