In order to investigate the molding process of polymer at low temperature under vibration force field，a ball-screw-electromagnetism-dynamic extruder was manufactured and a model for this molding process was developed.The molding mechanism of polymer at low temperature was studied，and the energy source for polymer molding was depicted with the dissipation energy resulted from vibration，deformation and shearing.An expression for the density of energy transform was obtained.Experimental studies and calculation were used to investigate the effect of vibration parameters.The results reveal that the calculation values are in good agreement with the experimental data.The vibration force field decreases the temperature for polymer processing (up to 40℃)，reduces the energy consumption (more than 47%)，and improves the tensile strength of polymer product.This work can serve as the theoretical and technical basis for polymer processing and equipment design.