Fused deposition molding (FDM) is widely used in 3D printing and thermoplastic filaments are usually utilized as printing material to print out products through the method of layer by layer (Wang et al., 2017 Yang et al., 2016a, Yang et al., 2016b). Three dimensional (3D) printing is to use the principle of “layered manufacturing, and layer by layer” to achieve the additive manufacturing, and the three-dimensional physical model can be accurately built by computer-aided design (Yang et al., 2016 Wang et al., 2017). The tensile properties of the TPU/WF composites were also greatly increased after the modification with EPDM-g-MAH. The examination of rheological properties of the TPU/WF composites indicated that the storage modulus, loss modulus and complex viscosity were significantly increased after the modification with EPDM-g-MAH. The XPS results indicated that the diphenylmethyl propane diisocyanate (MDI) and EPDM-g-MAH modification positively affected the interfacial bonding property between WF and TPU. SEM and FTIR results revealed a good compatibility between TPU and WF after the modification with EPDM-g-MAH. The results showed that the tear elongation decreased gradually as the WF content increased, and the tensile strength firstly decreased and then increased. The mechanical properties, microtopography and chemical structures of the 3D printing products were examined by the mechanical testing machine, scanning electron microscopy (SEM), Fourier transformed infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and rheological property tester. These filaments were fabricated through the melt-blending and melt-extrusion of TPU and WF. Using three-dimensional (3D) printing technology, the wood flour (WF)/thermoplastic polyurethane (TPU) composites with different contents of WF and different modifiers were prepared by TPU/WF composite filaments.