Abstract: In order to adapt to the development conditions of Maozhou Estuary,Lingding Bay,and ensure smooth flood discharge as the primary principle,and to comply with the law of water and sediment movement and river regime development,the regulation line of estuary is selected and optimized. The regulation line scheme is divided into single and double channels. There are two schemes of enclosure filling and enclosure filling and excavation under different broadening rates of the two types of channels. Mathematical simulation and physical model experiment of hydrodynamic sediment are carried out. The results show that the effects of various schemes of estuary regulation line on the rising and falling currents of Lingding Bay are mainly concentrated in Jiaoyi Bay and its adjacent waters,and that after the implementation of the scheme,the erosion and deposition in the surrounding waters have little change and have no adverse impact on the river regime. With the increase of the widening rate,the influence of scheme on the flood discharge in the estuary decreases gradually. According to comprehensive analysis of the impact on hydrodynamics,estuary flood discharge and river regime stability,compared with single-channel and double-channel,the impact on flood level,tidal volume,high and low tide level,flow velocity and riverbed erosion and deposition has good consistency. Under the same broadening rate,the impact of each scheme is of the same magnitude.