Abstract: Cellulose, which plays the role of skeleton in wood, exists in the cell wall in the form of microfibrils with different helical structures. In this paper, the fiber spiral reinforced structure of wood cell wall was studied by combining 3D printing technology with simulation. Using microcrystalline cellulose (MCC)/polylactic acid (PLA) composites, based on the testing of the properties of MCC/PLA composites, the spiral structure of wood cell wall was constructed with the help of 3D printing technology, and the mechanical function of the structure was programmed by changing the fiber orientation and fiber pore structure. Finite element simulation was used to emphasize the key role of fiber in the load transfer mechanism between rigid elements. The results show that the properties of the structure can be controlled by programming the orientation and structure of the fiber, and the cross structure of the fiber can be used to improve the mechanical properties of the structural molded products as an optimal design. These structures can be assembled into larger systems for building modular composites with optimized specific functions. It has potential application value in the field of hetero structure design and new composite material manufacturing.