Asynchronous online discussions (AODs) are increasingly prevalent in higher education to adapt to educational changes and promote critical thinking among learners. Past research has emphasized instructors' facilitation roles in encouraging learners' critical thinking in AODs, while fewer studies explored peer facilitation and peer participants' critical thinking from the students' perspective as facilitators. This study used a lag sequential analysis approach to examine peer facilitation techniques and critical thinking in a peer‐facilitated AOD spanning six tasks over 12 weeks with 40 undergraduate participants. Results highlighted that the most frequently used peer facilitation techniques were giving own opinions or experiences and questioning, with the latter demonstrating the highest number of significant sequential patterns. Peer participants' critical thinking primarily involved analyse and evaluate, with significant sequential patterns observed in lower level and higher order critical thinking stages but not between them. Further investigation revealed the impact of peer facilitation techniques on critical thinking, and a new three‐phase model was developed to describe their associations. These findings suggest that dynamic peer facilitation techniques effectively enhance critical thinking, with specific techniques targeting distinct phases of its development in AODs. The study provides actionable insights for educators, offering strategies to optimize facilitation approaches and foster critical thinking skills in higher education settings. Practitioner notesWhat is already known about this topic Asynchronous online discussions are widely used in higher education to encourage learners' critical thinking. Instructors as facilitators play a positive role in encouraging learners' critical thinking in asynchronous online discussions, while the role of peer facilitators is less discussed. In peer‐facilitated asynchronous online discussions, the facilitation techniques used by peer facilitators affect the development of critical thinking in peer participants. What this paper adds Uses lag sequential analysis to examine the sequential patterns of peer facilitation techniques and critical thinking in peer‐facilitated asynchronous online discussions. Reports common peer facilitation techniques used by peer facilitators and observed significant sequential patterns. Presents the distribution and developmental sequential patterns of critical thinking in peer participants. Examines the association between peer facilitation techniques and critical thinking, and develops a new three‐phase model to describe this association. Implications for practice and/or policy Dynamic peer facilitation techniques can effectively promote the development of critical thinking in peer participants, with specific relationships existing between different phases of critical thinking and different types of peer facilitation techniques. This study reveals the facilitation of critical thinking in asynchronous online discussions from the perspective of learners as facilitators, filling a research gap. The findings provide practical guidance for effectively encouraging critical thinking among college students in higher education.