In response to the requirements for interdisciplinary teaching outlined in the Compulsory Education Curriculum Plan (2022 Edition), this paper constructs a competency system for secondary school geography teachers in interdisciplinary teaching. The system encompasses five core competency elements: Geographic Spatial Integration, Interdisciplinary Teaching Design, Geographic Practice and Innovation, Interdisciplinary Evaluation and Reflection, and Disciplinary Education and Ethical Awareness. The paper elaborates on the connotations and characteristics of each element and proposes developmental suggestions from multiple perspectives, aiming to provide support for enhancing secondary school geography teachers’interdisciplinary teaching capabilities.