By analyzing soybean structural and physiological characteristic sufficiently, the paper proposes a plant structural controllable modeling method for soybean. It selects the key structural factors firstly, and collects the relevant field data. Then it extracts the organ structure and position laws along with their vertical and horizontal change to establish controllable structural model. Combined with structural growth model based on growth function, it could establish soybean dynamic structural model, which has great significance to optimize the field cultivation measure and design ideal plant type.