Abstract: The article uses the component data analysis method to systematically explore whether the movement behavior of preschool children(373 in total, 195 boys, 178 girls) is related to physical health, and the dose effect of the change of action behavior time and physical health status in movement behavior. The results show that: 1) The relative distribution of the movement behavior time of preschool children is closely related to physical health. The time spent on moderate-to-vigorous physical activity(MVPA) is probably the most stable. If there is a change, the probability of conversion from light physical activity(LPA) time is the highest; 2) MVPA of preschool children has positive influence on the improvement of physical fitness and body shape; 3) MVPA of preschool children has positive health benefits when isochronously replacing other behaviors, when LPA is replaced by isochronous,the benefit is the best; 4) the benefits of isochronous substitution are asymmetric. With the increase of MVPA isochronous substitution of other behaviors, the physical health of preschool children will slowly increase, otherwise it will decline rapidly; 5)when MVPA is constant, LPA and sleep(SP) isochronous replacement of sedentary behavior(SB) and SP isochronous replacement of LPA will have certain physical health benefits. In the future, educators should focus on the whole behavior, maintain and promote the physical health level of preschool children. It should be pointed out that increasing MVPA and decreasing LPA is one of the effective way to improve the physical health of preschool children.