The purpose of this study is to provide basic data that can enhance the happiness of childcare teachers by verifying whether grit moderates the effect of psychological burnout on subjective happiness via gratitude of childcare teachers. The subjects of the survey were 234 workers working at a daycare center in S city, and the data was analysed using SPSS Win. 25 and SPSS PROCESS macro4.2. The descriptive statistics analysis, reliability analysis, correlation analysis, and moderated mediating effect analysis were applied for data analysis. As a result of the study, first, psychological burnout showed a significant negative correlation with grit, gratitude, and subjective happiness, grit showed a significant positive correlation with gratitude and subjective happiness, and gratitude showed a positive correlation with subjective happiness. Second, grit moderated the relationship between psychological burnout and gratitude, and played a moderated mediating role in buffering the effect of psychological exhaustion on subjective happiness via gratitude. Gratitude and grit of childcare teachers acted as protective factors when psychological burnout decreased subjective happiness. Based on these results, when the psychological burnout of childcare teachers has a negative effect on subjective happiness, a plan to protect them by using gratitude and grit was proposed.