Abstract: Based on the ecological economics idea, by taking the water resources ecology-society complex system as the research object, it analyzes the functional characteristics, forms and dimensions of ecological water use outside river channel. Using the energy value analysis theory, aiming at the value of dilution and purification, value of cooling and humidifying, value of removing dust, value of carbon sequestration and oxygen release, net primary productivity and biomass, value of biodiversity protection, value of reclaimed water reuse, etc. to propose the emergy evaluation of ecological water use value outside river channel to realize the quantitative analysis and unified measurement of each sub-item value. Taking Zhengzhou as an example, the value of ecological water use outside the channel is calculated.