The vaccination rate of COVID-19 in preschool children is low, and parents’ intention to vaccinate their children is also low due to multiple factors. This study aimed to establish an integrated model based on the Health Belief Model (HBM)and Theory of Planned Behavior (TPB), to explore the factors influencing parents’ intention to vaccinate their preschool children with the first and second doses of COVID-19 vaccines. A total of 1264 parents of preschool children from 10 kindergartens participated in this study. Hierarchical multiple logistic regression was used to analyze the intention separately. For the integrated model with the first dose of vaccine of COVID-19, introducing the HBM variable in model 1 explained 33.98% of the variance (F = 398.71, < .001), then upon adding the TPB variable in model 2, the explanation of variance increased to 41.93% (F = 491.94, < .001) and parents' intention were associated with their perceived barriers, cues to action, and subjective norms. For the integrated model with the second dose of vaccine of COVID-19, introducing the HBM variable in Model 1 explained 23.76% of the variance (F = 68.82, < .001), then upon adding the TPB variable in model 2, the explanation of variance increased to 26.67% (F = 77.24, < .001), and parents' intention was associated with cues to action and subjective norms. The combination of the two theories improves the explanatory power of parents' intention to vaccinate their preschool children against COVID-19, and provides a basis for the development of effective interventions for vaccination of COVID-19 for preschool children.