The deep integration of information technology and college English teaching is the concrete implementation of the national education digitalization strategy in higher education. College English Teaching Guide (2020 Edition) clearly states that college English teaching should construct a new online-offline blended teaching pattern and focus on cultivating students’ autonomous learning ability and comprehensive English application ability. As a teaching tool integrating resource sharing, real-time interaction, process data monitoring and personalized push, the smart teaching platform provides key technical support for solving pain points in traditional college English classrooms such as “teaching replacing learning”, “disrupted teacher-student interaction” and “delayed learning situation feedback”. Based on the construction logic of autonomous classrooms, this paper deeply analyzes the technical mechanism of smart teaching platforms empowering autonomous learning, and constructs a closed-loop autonomous learning mode of “goal-process-evaluation” in the whole process before, during and after class. Meanwhile, in view of the practical dilemmas in current applications such as superficial platform functions, lack of students’ autonomous awareness and formalistic evaluation system, this paper puts forward optimization strategies including deepening function integration, optimizing task design, constructing a multi-dimensional evaluation system and strengthening teacher training, aiming to provide a replicable and promotable practical paradigm for college English teaching reform.