In view of the problem that how hydraulic structural designers can quickly obtain the cross-sectional dimensions of gravity concrete block quay,we apply the linear programming model to establish constraint equations,program under certain assumptions to solve the minimum ratio of width and height of the wall structure,and form a table of calculation results. The designers can look up the values of key variables in the calculation results table,use interpolation and other methods to obtain the minimum ratio coefficient,and get the minimum width of the wall structure of gravity concrete block quay. The results show that the method can realize the rapid design and improve work efficiency effectively.