Abstract: Aiming at the nozzle blockage and model drawing phenomenon caused by the disproportion of the melt extrusion speed and the nozzle scanning speed during the FDM molding process, the orthogonal test method and the ANSYS Fluent software are used to analyze the flow channel structure parameters and different printing in the nozzle carry out simulation calculation under parameter conditions, and carry out range analysis and single factor test result analysis to the orthogonal test results. The results show that the biggest factor affecting the melt extrusion speed is the wire feeding speed, followed by the nozzle inner diameter, and the smallest is the convergence angle, the length of the exit section and the printing temperature. The wire feeding speed is 60 mm/s, the nozzle inner diameter is 0.4mm, and the printing temperature is proposed. 210 °C, the length of the discharging section L=1.5 mm, and the convergence angle of 150° is the optimal process plan. Finally, an exponential prediction model between melt extrusion speed and influencing factors was established and the accuracy of the model was verified.