The invention provides a method for de-silting a lake and constructing a lake center island and belongs to a construction technology. The method comprises the following steps of: de-silting and dredging, transporting sludge, carrying out storage yard treatment, curing the sludge, discharging tail water and constructing the lake center island while de-silting. The method disclosed by the invention solves the problem that old problems of de-silted lake water happen again. The engineering cost is reduced, the work period is shortened and the secondary pollution is managed. The method has the characteristics of smaller occupied space, no transferring of pollutants, investment saving and good benefits. According to the method disclosed by the invention, the swampiness problem is solved, the water storage amount is increased, a land resource is increased, a wetland park is established and the pollution recycling is realized. The method is a practical and feasible good method for managing and beautifying the lake.