A boundary scan method, including generating a first parallel unipolarity boundary scan signal by a scan signal generation apparatus, sending the first parallel unipolarity boundary scan signal to a boundary scan controller; and converting, by the boundary scan controller, the first parallel unipolarity boundary scan signal into a serial boundary scan signal in a differential signaling form, and using the serial boundary scan signal for scanning a boundary scan device connected between a scan signal output and a scan signal input of the boundary scan controller.