Abstract: Magnesium alloys have the characteristics of lightweight, high specific strength, excellent shock absorption and high biocompatibility, which have great potential for the application in the fields such as aviation, aerospace, and biomedical engineering. However, the traditional processing techniques can hardly achieve the preparation of the integrated complex structural components, having seriously restricted the application and popularization of the magnesium alloy parts. Additive manufacturing technology is an advanced technology based on the principle of "discretization+stacking", which is expected to become an important technological approach to solve the problem of complex and difficult machining of thin-walled structural components of the magnesium alloys. In this study, an internal mixer is adopted to mix polymer binder with magnesium alloy powders, and an extrusion machine is employed to prepare wire materials suitable for the fused deposition modeling (FDM) process. The influence of FDM process on the surface morphologies of the green billets is investigated. The orthogonal experiments and data statistics are used to analyze the influence of process level factors on the dimensional accuracy, and the improvement directions for the subsequent sintering processes are proposed.