It is still a challenge for students to engage in classroom dialogue actively and realize effective dialogue-based learning, as classroom dialogue are influenced by a multitude of factors. It is reasonable to believe that by delving into a specific variable (perceived care) to gain insights into its potential impact on dialogue engagement, which deepen the understanding of teacher-student relationships in the classroom. This study investigated dynamic teacher-student dialogues and their association with students' perceived care by adopting a mixed method. In WSZ-AI System developed by our research group, 71 students and a teacher from Grade Seven were selected in the research firstly. A coding scheme for student discourse engagement was developed and the coding scheme for teacher talk support was employed. Based on these two coding schemes and technology-assisted coding, all teacher-student dialogues are coded in every turn-taking. Finally, lag sequence analysis and state space grid analysis are used to analyze dynamic dialogues and its relationship with student perceived care, and interviews are used to verify the results of quantitative analysis and understand students' perception of classroom dialogue. In addition, we also analyze the differences between various achievers in high perceived care (HC) group and low perceived care (LC) group. Quantitative results demonstrated that teacher-student dialogue patterns are related to the students' perceived teacher care. The interaction patterns were more stable in students who perceived high teacher care as well as their discourse engagement status over the semester. The follow-up qualitative results show that the teachers' talk supports affect students' perceived care and students with high perceived care are more willing to engage in their dialogue. Concerning the importance of student-perceived teacher care, this study provides a unique perspective for educators to establish a safe and supportive classroom environment which promotes the students' dialogue engagement and provides scaffolding and support to help students complete knowledge construction.