Fused deposition modeling (FDM), one of the 3D printing techniques, is widely studied because of its fast, safe, simple operation and many other advantages. At present, the materials that can be applied to FDM are limited, most are ABS and PLA, with much higher price. It is urgent to develop new materials of high performance price ratio and multi function for FDM. In this paper, the PVA/PLA blend with good biocompatibility was prepared and the deposited part of PVA/PLA was successfully deposited by FDM. The effect of processing parameters on the structure and properties of the deposited parts were studied. Through the theoretical analysis of the feeding process of FDM, it was found that feedstock materials can feeding smoothly and without buckling during FDM, then the ratio of compressive modulus to apparent viscosity must higher than a critical value, i.e, 3.24×105s-1. Based on the intermacromolecular complexation and plasticization, by using the efficient modifier with water, the thermal processing of PVA was realized. Blending PLA with PLA, the C=O on PLA molecular chains can interact with OH on PVA chains, thus further reduce the PVA intra- or inter-molecular hydrogen bonds, reduce the viscosity of the melt. Thus makes the ratio of the compressive modulus to viscosity higher than the critical value, enables the material suitable for FDM. The relationship between the ratio of compressive modulus to apparent viscosity and the feeding properties of the materials in FDM were studied. The theoretical analysis was verified by experiments. The effects of the parameters such as the layer thickness, air gap, as well as raster angle on the structure and properties of PVA/PLA parts produced by FDM were studied. Through the three-dimensional scanner and the Geomagic Control software, the data of the hemisphere CAD data model and hemisphere prototype part produced by FDM were fitted and analyzed. By the reverse analysis method, from the three dimensional integral as well as the two-dimensional plane, the accuracy testing of the FDM part was conducted. This work was supported by the National Natural Science Foundation of China (51433006).