According to the Inland river navigation development plan of Sichuan Province，there are 14 steps planned in the Jialing River，and the section from Guangyuan to Zhaohua will reach the Grade IV waterway standard by 2030. However，due to the Comprehensive planning for the Yangtze River basin，the Shuidong dam junction of the Jialing River was cancelled，the water level between Tingzikou and Shangshipan junction cannot be connected. The designed water level variation range of Tingzikou hydropower station is as high as 20 m，which results in a fluctuating backwater area of about 28 km at the end of the reservoir. The natural flow of this waterway section is very small，and the planned grade IV waterway cannot be achieved only through waterway regulation. Therefore，this paper adopts the method of good river section correlation to establish the river correlation under the characteristic flow between the beach dangerous riverbed after regulation section shape and the good river section，and infer the stable navigation depth that may be achieved by the beach dangerous riverbed regulation under different flows，so as to find the minimum flow of the engineering reach that meets the water depth standard of Class IV channel. Then the paper analyzes the time of occurrence of this flow based on the data from the hydrological station，combined with the characteristic water level backwater mileage of the Tingzikou Power Station，studies the navigation guarantee rate by segment，and proposes the flow rate and guarantee rate for the variable backwater area at the rear of the Tingzikou Reservoir to reach the planned level IV channel.