Abstract: To solve the universal problem of fuze arming device using magnetorheological fluid (MRF) for small caliber artillery,the integrated influence of device structure,characteristics of MRF and environment parameter on delay arming time was analyzed,and the control ability was confirmed through equivalent rotation experiment.In the analysis of the structure of the hole,the hole pattern,aperture and hole length were analyzed,and the aperture was designated as control parameter.In the analysis of characteristic of MRF,through the viscosity equation deduced based on the Herschel-Bulkey model and viscosity-temperature experiment,the influence factors of the viscosity were determined when MRF discharged.Finally,through changing the aperture and configuration of MRF,the ability to control delay arming time was well studied under 60 000~90 000 r/min rotation speeds in equivalent rotation experiment.The results indicate that the delay arming time can be controlled effectively when the configuration of MRF is 7:1、8:1、9:1 and aperture is 0.26~0.30 mm,and the device has good universality under these conditions under 60 000~70 000 r/min rotation speed.