Objective: This study aimed to explore the factors influencing Chinese English as a Foreign Language (EFL) learners’ interactive learning in an online learning context. The objectives were to identify these factors, understand their mechanisms, and develop a theoretical model that encompasses these elements. Methods: The research employed a grounded theory approach to analyze interactive data from the discussion forums of the Course of College English on China university Massive Open Online Courses platform. Data were collected from 3,279 learners during the Fall 2023 semester. The analysis proceeded through open coding, axial coding and selective coding to identify and categorize the influencing factors. Results: The study identified six main categories: learner characteristics, curriculum structure, teaching competence, expected outcomes, interactive behaviors, and online learning context. These categories were found to be dynamically interconnected, collectively shaping learners’ interactive behaviors and overall learning experiences. The core category, “EFL online interactive learning”, unified all these elements, highlighting the multifaceted nature of effective EFL online education. Conclusion: The findings underscore the importance of understanding the interplay between various factors in the EFL online learning environment. The developed theoretical model provides a comprehensive framework for enhancing EFL online education by addressing learner needs, improving curriculum design, and ensuring robust teaching and technological support. These insights offer valuable implications for educators and policymakers aiming to improve online EFL learning outcomes.