A landslide will occur when the channel is scoured by the ship’s waves or in the process of widening. Based on the DP yield criterion and the ideal elastoplastic theory，the relation of the soil between strain and stress is derived. On this basis，the accumulation shape of landslide bodies with different cross-section ratios is studied by the SPH method. Two dimensionless parameters are used to describe the characteristics in the height and length directions，and the accuracy is tested by compared with experimental formal. The influence of height-length ratio on the contour of soil body is studied under the same cross-sectional area condition. The research results show that：1）The dimensionless parameters under the description framework used here are in good agreement with the computational values in the literature.2）With the increase of the height-length ratio，the yield zone of the slope will be larger，but there is not much difference in the outline of the landslide body.