Sand pillow is a new material for throwing to protect banks，which has the advantages of stable structure and low construction cost.Previously used traditional throwing empirical formula requires the measurement of the water depth and velocity data before each throwing，with few models used to simulate the three-dimensional flow field，which consumes manpower and material resources.In order to improve construction efficiency，this paper uses the six-layer method and the eleven-layer method to predict the drift distance of the sand pillow respectively in combination with the Mike3 hydrodynamic model and the drift distance formula of the sand pillow by analyzing the vertical stratified flow velocity，and the paper finds that the eleven-layer method is more precise.