This paper summarizes the research achievements on erosion-siltation balanced flow of Xinyanggang Sluice,and analyzes the erosion-siltation conditions and general laws of channel downstream sluice for 2012. Based on the data related to the erosion-siltation and water regime during the period from 2008 to 2012, the effects of discharging runoff on the erosion-siltation of the channel downstream the Xinyanggang Sluice are mainly analyzed with correlation analysis method. The results show that to keep the channel stable, the floodgate is not suitable to be closed for a long time and the ratio of undrained days accounting for total days should be less than 42％ in non-flood season. Runoff and tides interact on sediment transport capacity of flow, and the unbalanced sediment transportation at flood and ebb tides in channel can be improved by runoff conditions. Sediment can only be carried 7 to 9 km seaward by weaker ebb currents, so large discharges for long time will be useful for stability of the channel. When the channel reaches the equilibrium state of erosionsiltation, there is a relationship between daily average discharge(Q) and the average cross-section area(A) of the channel(i.e.,Q=0.13A). In the present channel regime, for proper functioning of the channel, the area is approximately 664m² and the daily average discharge is approximately 86m³／s.