Abstract: Contact electrical appliances are widely used in the switch electrical appliances, and their operating status will directly affect the operation of the entire power system. So the performance evaluation of contact electrical appliances is significant. This paper investigated a contact electrical performance degradation evaluation test system. Take AC contactor as an example, the use of NI high-speed data acquisition card, which achieves simultaneous acquisition of 8 channels. And Labview virtual instrument technology is used to real-time control of the slave computer through the serial communication, so that monitoring and recording the accurate voltage and current waveform data of the coil and main contact during the test process of AC contactor. The characteristic parameters which reflect the degradation of AC contactor can be extracted from the collected accurate waveform data, which lays a foundation for the further research on performance degradation assessment.