Abstract: Abstract：With the rapid development of the information technology and computer technology, the study of plant in nature simulation has become one of the hot researches in computer graphics. This paper mainly introduced OnyxFLOWER which is a 3D modeling software based on the multi-level topological structure of flower, analyzed the methods and characteristics of modeling and took Lilium longiflorum as the example, aiming to offer way and method for the developing research.