The invention relates to an ultrasonic wave scanning method and an ultrasonic wave scanning device. The ultrasonic wave scanning method comprises the following steps: providing a wafer to be scanned,wherein the wafer to be scanned is arranged on a base station; from the initial scanning position of the edge of the base station, adopting ultrasonic wave to carry out line-by-line scanning, and acquiring the reflected wave waveform of the ultrasonic wave, wherein the reflected wave waveform comprises a first waveform, and the first waveform enters the reflected wave waveform of the base stationarea from the wafer area by corresponding to the scanning position; when the first waveform is acquired, moving to a next line for scanning, wherein a scanning direction is opposite to the scanning direction of a previous line.