The profound changes in learning methods and the rapid evolution of educational forms in the digital age necessitate a re-examination of instructional theory in terms of conceptual boundaries, applicability conditions, and theoretical explanatory power. To develop a teaching theory system aligned with the demands of the digital age, this paper adopted the method of literature analysis to systematically sort out the basic concepts, paradigmatic roots, theoretical structure and development logic of teaching theory. Firstly, based on the conceptual definitions of educational research paradigms, learning theories and instructional theories, the intrinsic connections at the philosophical orientation level among the three were analyzed. Secondly, it explored the definitions of the essence of learning by eight educational technology paradigms and their development trends in the context of digital education, explaining that social interaction, technological adaptability and paradigm integration have become the key features of the evolution of learning theories in the digital age. Finally, centering on classic instructional theories, their commonalities and differences were compared, and their adaptive changes in digital education were summarized, including dynamic adaptation, technological extension, innovative development, and cross-theoretical integration, among other directions. Research showed that the development of teaching theories mainly focused on positivism and interpretivism paradigms, with constructivism and social constructivism exerting particularly profound influence. However, the exploration of teaching theories by the critical and pragmatic paradigms still needs to be deepened. By systematically examining the teaching theoretical system, this study elucidated its structural characteristics and contemporary shifts, providing theoretical support and future directions for constructing a teaching theoretical framework suited to the digital age.