How to accurately detect the motion parameters of the operating mechanism and study the influence of the motion characteristics on the arc combustion process is one of the important research topics in the field of vacuum switching breakers（VCBs）. A speed detection method based on a Labview virtual instrument development platform is proposed in this paper. The contacts images are collected by high-speed camera in the interrupting process

and the image processing module of Labview is used to accurately position the edges of the moving and static contacts. Moreover

the motion parameters of the contacts in three different stages of arcing

arcing and arc extinction are calculated

and the effects of the motion parameters on the arc combustion characteristics are combined analyzed. The experimental results show that the average opening speed

the straightening speed and other motion parameters of the vacuum switching breakers can be effectively detected by the proposed method

and the method has the characteristics of high sensitivity

transient response

no loss of parameter data

etc. the research can provide technology foundation for the researches on dynamic characteristics of vacuum switching arc.