Graph theory was introduced into landscape ecology research at the end of the 20th century, and gradually formed the methodology system of landscape graph. The theoretical basis of landscape graph is graph theory and metapopulation theory. At present, landscape graph is widely used in research related to landscape ecological networks. Its research methods mainly include the construction of landscape graph and analysis of landscape graph indices, etc. Its application fields mainly focus on landscape connectivity assessment, habitat protection, landscape impact assessment and ecological network optimization. Landscape graph method has presently some limitations in practical application, such as the human subjectivity in model parameters assignment and the insufficient model verification. This paper provides an overview of the theoretical basis of landscape graph, and reviews the construction methods, index systems, application fields, problems, and prospects of landscape graph in ecological network research, with the aim of providing references for researchers, ecological planners, and managers.