In the context of widespread digital transformation in education, the digital management capacity of high school principals has become a key factor to ensure effective leadership, improve educational quality and adapt to innovation requirements. This article focuses on analyzing the needs and factors affecting the development of digital management capacity for high school principals in the Mekong Delta region, a region with diverse economic, social and technological infrastructure conditions. Based on a mixed research method, including a survey of 115 principals, vice principals, professional team leaders, and in-depth interviews with 12 managers, the article identifies necessary groups of competencies, such as educational data management, digital platform deployment in teaching and learning, information security, and digital transformation leadership. The research results show that five factors have a significant impact on the capacity development process, including: policy clarity, quality of technology infrastructure, innovation orientation in leadership, professional development opportunities, and coordination between schools and local authorities. From there, the article proposes policy and practical recommendations to build a roadmap for developing digital management capacity for principals, contributing to promoting educational innovation in the digital age in Vietnam.