Inter‐basin water transfer projects (IBWTPs) offer one of the most important means to solve the mismatch between supply and demand of regional water resources. IBWTPs have impacts on the complex ecosystems of the areas from which water is diverted and to which water is received. These impacts increase damage or risk to regional ecological security and human wellbeing. However, current methods make it difficult to achieve comprehensive analysis of the impacts of whole ecosystems, because of the long distance between ecosystems and the inconsistency of impact events. In this study, a model was proposed for the analysis of the impacts of IBWTPs on regional ecological security. It is based on the telecoupling framework, and the Driver‐Pressure‐State‐ Impact‐Response (DPSIR) model was used to improve the analysis procedure within the telecoupling framework. The Middle Line of the South‐to‐North Water Diversion Project was selected as a case study to illustrate the specific analysis procedure. We realized that information sharing is a key issue in the management of regional security, and that the ecological water requirement, in the form of a single index, could be used to quantitatively assess the impacts on ecological security from IBWTPs.