Abstract: The needle bar and the thread take-up device are the main mechanisms to form the stitch of the embroidery in a computerized embroidery machine.Since the needle bar and the thread-taking-up mechanism are fixed to the beam of the computerized embroidery machine,the bending vibration of the beam is very important for forming high quality stitch of the embroidery.The study is directed to the beam of a computerized embroidery machine with 2 driving mechanisms.Its bending vibration test in vertical and horizontal directions has been undertaken in four running cases,i.e.,the upper axis,the lower axis,the upper and lower axis,the overall machine.The natural frequency,response amplitude of the displacement,velocity and the acceleration rate of the bending vibration of the beam have been acquired.This paper put forward a concrete way to improve the structural design of the beam of the computerized embroidery machine,and its conclusion is applicable for it.