The field of education has long emphasized the importance of kindergarten teachers perceiving and understanding students' thoughts and feelings and expressing concern, commonly referred to as teacher empathy. However, little work has focused on the "cost of caring," such as compassion fatigue, particularly among kindergarten teachers, which poses a significant threat to their physical and mental health. To identify the factors that shape compassion fatigue and explore the mechanisms underlying these relationships, a serial mediation model was proposed involving mindsets of empathy, teacher empathy, professional identity, and compassion fatigue. In the present study, self-report measures were administered to 2256 kindergarten teachers to assess the major variables. The serial mediation model was evaluated using the Process macro software, and the results showed that compassion fatigue can be significantly and negatively predicted by mindsets of empathy, with teacher empathy and professional identity mediating this relationship among kindergarten teachers. These findings substantially contribute to the understanding of compassion fatigue among kindergarten teachers and provide valuable implications for its interventions.