With the development of technology and the normalization of COVID-19 pandemic prevention and control, asynchronous online learning is becoming popular. However, it is still to be explored on how to enhance students' learning engagement and knowledge construction. Based on this, we used content analysis to explore the roles of teaching strategies (i.e., contextual teaching strategy, organization teaching strategy, task-driven teaching strategy, and reflective teaching strategy) in students' learning engagement and knowledge construction (i.e., questioning level and explaining level). The comparative analysis results indicate that: (1) task-driven teaching strategy could be used to increase students' learning engagement. (2) task-driven teaching strategy could be used to enhance students' questioning level. (3) reflective teaching strategies could be used to improve students' explaining level. The findings could provide theoretical and practical implications for asynchronous online learning. It is helpful to optimize online teaching design and improve the effectiveness of asynchronous online learning.