Abstract: In order to test interrelated parameters of flyer of fly frame,a new testing system was developed.A differential mechanism of hybrid driving which imitates the variation of cylinder′s diameter was introduced for the first time so as to test the changing law of press palm strength of the flyer of fly frame at different rotating speeds when winding.It includes the mechanic transmission,control and signal processing system and can realize automation of control and data collecting and processing.The experimental results show that it meets the needs of technology and design,runs steadily,operates easily,and has accurate tests.