In order to materialize the on-line ultrasonic testing of workpiece,a data acquisition system for the product family of machine tool ultrasonic testing accessories was designed.In hardware design,the types of data acquisition card and ultrasonic flaw detector were selected.In software design,LabVIEW was used as platform,the modular design idea was used to design the data acquisition system.Eventually,a kind of data acquisition system was designed,which hardware included CTS23 flaw detector and AC6684A/D card and the software was taken LabVIEW as platform.The data acquisition system can be applied to the machine tool,materializing the on-line detection function of the product family.