Electronic device and method for phase detection autofocus

The present disclosure discloses a method for phase detection autofocus and an electronic device thereof. The method is applicable to an image capture device and includes the following steps: calculating a plurality of phase difference values and a plurality of defocus values of a focusing image by a lens of the image capture device, wherein each of the phase difference values corresponds to a defocus value; grouping the phase difference values into a foreground group and a background group; determining a foreground focus position by the defocus values corresponding to the phase differences in the foreground group; determining a background focus position by the defocus values corresponding to the phase differences in the background group; determining an ideal focus position based on a depth of field of the focusing image, the foreground focus position and the background focus position; and moving the lens to the ideal focus position.