Provided is a portable electronic device, including a photosensitive control device, a host portion, and a display screen pivoted with the host portion. The display screen comprises an array substrate. The photosensitive control device comprises a photosensitive element, a sensing driving circuit, and a control module connected in sequence by signals. The photosensitive element is formed on the array substrate and is on a non-display region of the display screen, to sense external light. The sensing driving circuit provides driving signals to the photosensitive element, and receives inductionsignals of the photosensitive element. When intensity of the induction signal is equal to or lower than a threshold, the control module generates a sleep control induction to control the portable electronic device to sleep. The threshold is intensity of the induction signal generated by the photosensitive element when the display screen is covered on the host portion. The photosensitive element formed on the array substrate is used to sense external light, and the device goes to sleep when the intensity of the induction signal is equal to or lower than the threshold, and the photosensitive element can replace a magnetic switch, and integration degree is high, and cost and assembly difficulty are reduced.