An ultrasound scanning method includes the steps of emitting N sets of ultrasound signals onto a target from N different angles and receiving the N sets of ultrasound signals reflected and/or scattered by the target; converting the N sets of ultrasound signals into N ultrasound input images; performing a binarization algorithm for the N ultrasound input images to obtain N binarized images; performing a comparison process on the N binarized images to determine whether a noise exists in at least one of the N binarized images; when the noise exists in an i-th binarized image of the N binarized images, removing the noise from an i-th ultrasound input image corresponding to the i-th binarized image; and compounding the N ultrasound input images into an ultrasound output image.