The reentry process of reusable launch vehicle is very complex, so extrapolating the landing area based on original state has significant meaning for the launch vehicle reentry trajectory. This paper presents a method of calculating the landing area based on dynamic programming. The method traces out a nominal resistance boundary curve in energy-resistance space on the premise of meeting all the constraint conditions of reentry trajectory, then tracks it by using feedback linearization to get the feasible boundary, finally attains a resistance project by using interpolation method. Longitudinal trace is also attained by using feedback linearization, while transverse control is achieved by tilting motion at different times. Select the largest and the least resistance values as the top and the bottom point of the reentry landing area, and at the same time choose the point that its tilting angle is constant plus or minus as the left or right side of the reentry landing area. All these above compose the boundary of the reentry landing area. At last, validate the feasibility of the method by computer simulation, and achieve a superior predictive result.