As a new type of hydraulic structure,the monolithic lock chamber structure with relieving platform has been used in Huihe Nanping lock chamber engineering.Using FEM numerical simulations,the influences of the height,width and thickness of the relieving platform on the horizontal displacement,soil pressure and bending moment distribution of the lock wall are analyzed.In the case of constant width and thickness of the relieving platform,with the increase of the relieving platform height,the horizontal displacement of the lock wall tends to decrease and then increase，and similar patterns can be applied for the width and thickness of the relieving platform.With the increase of the relieving platform height,the soil pressure of the lock wall above the relieving platform changed little,the soil pressure of the lock wall under the relieving platform tends to decrease and increase，and similar patterns can be applied for the width and thickness of the relieving platform.The upper part of the lock wall is the positive bending moment,and the lower part is the negative bending moment.The height,width and thickness of the original scheme are reasonable.