In the context of digital transformation in education, increasing importance is attached to addressing individual differences among students in foreign language teaching. From the perspective of Multiple Intelligences Theory, this article analyzes the practical challenges involved in implementing differentiated instruction in senior high school English classrooms. The study adopts a qualitative research approach, including semi-structured interviews with six English teachers, classroom observations of twelve lessons, and analysis of instructional materials. The findings indicate that differentiated instruction is often implemented in a formalistic manner in practice: the dominance of a unified teaching model persists, teachers demonstrate a superficial understanding of Multiple Intelligences Theory, multifactor assessment remains limited, and the potential of digital educational technologies is insufficiently utilized. These issues reveal a gap between theoretical principles and their practical application. To address these problems, the study proposes optimizing teacher professional development, reconstructing the teaching process based on student-centered principles, and rationally applying digital tools to support students’ individualized development and improve the quality of English teaching in senior high schools.