The online education ecosystem is a community structure, a development phase of online education, which is formed with the enrichment of the contents of online education, the diversification of population, the continuous optimization of the internal and external environment of the system, and the maturity of operation mechanism. From the perspective of ecology, the Logistic Model is introduced to explore the dynamic growth of the population in the system, and the symbiotic evolution dynamic model is constructed on the basis of symbiotic theory to research the coevolutionary mechanism between central population and satellite population under different coevolutionary models. The results show that the growth of online education enterprises is fit to Logistic curve and is currently at the rapid growth period. The equilibrium state of coevolution between populations depends on symbiotic coefficient and environmental resource constraints. Mutualism symbiosis mode is the ideal mode; however, the parasitic mode and partial interest symbiosis mode dominate at present. Therefore, we should optimize the ecological environment, keep population diversification and ensure the improvement of ecosystems education and business efficiency.