Based on the data of 12 representative cross-sections in the Lower Yellow River from October 2006 to November 2018, the adjustment process and characteristics of downstream riverbeds during the continuously scouring period is investigated by analyzing the variation rates of the morphology characteristic parameters of the main channel and the migration intensity of the thalweg and the centerline. The results show that the morphological adjustment of the Lower Yellow River has exhibited a diversity with both lateral widening and vertical scouring or depositing in recent years.The riverbed migration has promoted the adjustment of the cross-sectional morphology of the main channel. The rate of change in cross-sectional geomorphic coefficient was positively correlated with the migration intensity of the thalweg and the main channel centerline. Furthermore, water-sediment condition is the main contributor to the changes in the main channel morphology, causing an increase in the migration intensity of the thalweg in local reach. Hence, a stable medium-size river channel of the Lower Yellow River will be further shaped and maintained when the operation mode of the Xiaolangdi Reservoir is adjusted and the reasonable river control work is established.