As an important part of ecological security pattern, the scientific setting of the width of ecological corridors is a crucial part of the planning and design. We reviewed literature about ecological corridor width, comprehensively sorted out relevant theories, summarized the extraction methods of ecological corridor width, and put forward future research directions. There are four categories of methods for extracting the width of ecological corridors: determining the width based on the range of movement of protected targets, referencing previous research, considering the cumulative current changes in circuit theory, or combining with other models. The influencing factors included ecological needs of protection targets, edge effects of corridors, construction costs, policy priorities, and others. There are different methods for determining the width of ecological corridors, but the degree of refinement needs to be improved. Future research should focus on the theoretical basis of ecological corridor width, refined setting methods, effectiveness verification, shape, etc. This review could provide effective ideas for ecological corridor width research and enhance the feasibility of its implementation.