Abstract: The paper proposed a design scheme of on-line monitoring system for mechanical characteristics of high-voltage vacuum circuit breaker based on DSP and LabVIEW.Data acquisition system of lower computer of the system takes DSP as core,which completes collection of mechanical characteristics parameters,current signal and vibration signal of on-off switching through sensors,signal conditional circuit and so on,and can realize display in-situ and transfer data to upper computer through CAN bus to be displayed and analyzed.Upper computer management system takes LabVIEW as development platform and uses its functions of graphic display and communication with Matlab to realize display,analysis and processing of measurement data.The field test result showed the system runs steadily with better accuracy.