Abstract:Based on FDM rapid prototyping manufacturing，the plastic tensile specimen was formed by using the biodegradable polymers-poly anhydrides(PLA) filament．A comprehensive consideration that how the processing parameters of filling density，layer height and filling path affect the mechanical properties (tensile strength， elastic modulus，etc．)， forming precision， forming time and cost on the sample was made．By processing and analyzing the experimental data，it is concluded that the parameters was setting in the different needs of the matching value， which provide effective reference for the optimization of FDM process and improve the precision．