As the most widely used hydrological method at home and abroad, the Tennant method plays an important role in the study of ecological base flow; however, as an empirical method with limitations, we should analyze its rationality when refer to or apply it. We systematically summarized the three key problems of the current ubiquitous spatial and temporal changes, weak flow suitability, and poor general conditions. Based on three improved forms: characteristic flow, water-use period, and percentage, we studied the improvement strategy of the Tennant method, and further summarized three improvement methods: the annual average method, the simultaneous mean method, and the improved percentage coefficient method. Finally, we selected low-flow indicators with annual and inter-annual variability to establish a cluster of adaptation curves between the percentage of base flow and aquatic habitats, and to target the correction of aquatic organisms in specific rivers. Physical needs and the determination of the ecological base flow threshold need to take into account the development trend between the flow and the river ecosystem, in order to broaden the scope of use of the Tennant method and improve the technical support of river ecological base flow in different regions.