This study aimed to explore practical strategies for enhancing the competencies of preservice early childhood teachers in teacher–child interactions by examining the mediating effect of teaching competencies on the influence of emotional intelligence on teacher–child interactions. A total of 180 preservice early childhood teachers were enrolled in early childhood education programs in Gyeonggi and Incheon. Descriptive statistics, correlation analysis, path analysis, and mediation analysis were conducted using structural equation modeling for data collection and analysis. The study results revealed the following key findings: First, the emotional intelligence and teaching competencies of preservice early childhood teachers directly influence teacher–child interactions. Second, the emotional intelligence of preservice early childhood teachers indirectly affects teacher–child interactions through teaching competencies. Emotional intelligence was confirmed to have an indirect effect on teacher–child interactions through teaching competencies, which is greater than its direct effect. In conclusion, these findings indicate that education aimed at improving emotional intelligence and teaching competencies is essential for enhancing teacher–child interactions among preservice early childhood teachers.