Urban river eco-security completely reflected continuous mutual impacts and conductions among many factors, such as the increment and the decrement of urban environment pollution, the type of land use, the technology to water conservancy engineering, the policy of ecological conservation. However, our early warning system of urban river eco-security was not perfect. In this study which aims to construct the urban vision for the urban river eco-security structure analysis, quantitative measurement and strategy simulation. This research , construction of five subsystems, “drainage control” ,”purification ability”, “water recycled”, “habitat” and “biomass”. A dynamic model of urban river eco-security forecast and simulation system was constructed by system dynamics software Vensim DSS 5.9. The error value between simulation and real situation are few to prove the model is effective .The study results indicate that the eco-security for Danshui River is going to biomass raising, drainage raising, Habitat increasing and pollution reducing. The cogitation has integrated by system dynamic model which coming together to form precaution,water use,conservation and ecological restoration. It is clear that urban river eco-security model may provide an alternative choice of urban river Engineering Construction decision and correspond to the direction of sustainable city.