Abstract: Inspired by the suture joint structure in nature, models of composite bionic suture joint structure with different orders of hierarchies were investigated based on the principle of graphic fractal. The law of interfacial damage extension and structural loading mechanism of joint structure were studied using commercial finite element software ABAQUS. The influence of structural interlocking feature, number of teeth and shape of teeth on the structural loading capability of the high-hierarchy suture joint structure was analyzed. The results show that the structural interlocking feature of the high-hierarchy suture joint structure improves structural loading capability significantly and changes the structure damage mechanism. Increasing the number of joint teeth on the unit width properly and changing local feature of joint teeth can reduce stress concentration and improve mechanical property of suture joint structure. The research explains the mechanical principle embodied in the process of evolution for the suture joint structure in nature, and provides new insights for the development of new engineering joint structure.