In view of the method of determining ecological water level and ecological flow in the highly artificial urban rivers being far from mature, this paper analyzes the characteristics and ecological functions of highly artificial urban rivers, analyzes the connotation of ecological water level and ecological flow. From different perspectives of connectivity of river, aquatic habitat, water quality assurance, urban landscape entertainment function, an practical calculation method is put forward considering river morphology, river aquatic life, water quality and landscape recreation. Taking Qinhuai River in Nanjing as an example, the ecological water level of the four channels such as upper section of Qinhuai River, lower section of Qinhuai River, outer section of Qinhuai River and the new Qinhuai River, l is 6. 8m, 6. 7m, 6. 3m, 6. 7m, respectively, and their ecological flow is 20. 8 m³/s, 25. 8 m³/s, 26. 5 m³/s, 19. 1 m³/s, respectively. The calculation results are between “good” and “very good” according to the Tennant standard, showing that the calculation method is reasonable and credible.