There is a significant gustloads difference between the normal discretegust model and continuousturbulence model because of the strong lift nonlinearity of a low speed medium altitude long endurance(MALE) UAV. To solve this problem, an improved discretegust model is adopted, namely, the kinematic equation of gust load is solved and the nonlinear lift is also considered during the moving course. Result indicates that the gust load obtained by the improved method is smaller than that by normal discretegust model, and which is close to the actual gust load. At the same time, the gust load is accordance with that computed by continuousturbulence model.