In order to manage rivers more effectively, a river ecosystem health early warning model based on the existing study of river ecosystem health and BP artificial neural networks was established and applied in the early warning of the Luanhe River's health status. The results show that the ecosystem health of the Luanhe River will be improved in the next 20 years: in 2015, its health will be in a mild disease state, corresponding to the middle warning level, and in 2020 and 2030, its health will be in a sub-health state, corresponding to the lower warning level. Measures to improve the ecosystem health of the Luanhe River, including water conservation, optimization of water supply projects, and water pollution mitigation, are proposed on the bases of future warning levels and warning sources.