Visual modeling is the theory, method and technology of using computer graphics and image processing technology to convert data into graphics or images, display them on the screen, and process them interactively. The growth and development of rice is a very complex systematic process. Rice leaves are the main organs for photosynthesis, nutrient production and transportation. With the help of computer technology, a visual model of rice leaves is established, which can provide auxiliary decision-making for scientific cultivation and yield improvement of rice. Based on VC++ and OpenGL, according to the three-dimensional morphological characteristics of real rice leaves, the mathematical model of rice leaves was established by using mathematical knowledge. B-spline curve is selected to simulate this, and the recursive definition and formula of B-spline curve are used to realize the modeling of rice leaf edge curve and main vein curve, so as to further realize the triangular mesh model of rice leaf in two-dimensional plane. Based on the mathematical method of main vein integral, the different bending effects of main vein vertex in different positions are realized. Finally, the uniform B-spline curve was used to establish the rice bending model and triangulate it. the method of using B-spline curve to describe the information of edge vein and main vein of rice leaves can better reflect the characteristics of leaves, so that the three-dimensional visual modeling of rice leaves is only related to the edge curve of vein, main vein, maximum leaf width, maximum leaf length and other information.