In this paper, the “root box method” was used to analyze the distribution pattern of the rice root system in soil. The production rule is derived by using the 3D spherical turtle geometry interpretation based on the parametric L system. The quadratic B-spline interpolation function is used to design the parametric L system. The visualization of rice root growth is realized by using Visual C++ and OpenGL Standard Graphics Library. The model is verified by experiments with the standard error approaching 0 and the consistency index approaching 1. It is found that the expected goal is achieved.