The embodiments of the present invention relate to an information terminal, comprising a display screen and a communication device, and also comprising a camera, a photo capturing unit, a photo gray level analysis unit and a display screen display parameter adjustment unit. The camera is used for acquiring a photo analog signal or a photo digital signal of a background environment within the viewing angle of a user, the photo capturing unit converts the photo analog signal or the photo digital signal acquired by the camera into digital photo data; the photo gray level analysis unit analyzes the gray level of the photo data, generates state parameters of the background environment within the viewing angle of the user according to configuration parameters of the camera, and sends the same to the display-screen display parameter adjustment unit; and the display screen display parameter adjustment unit adjusts the display parameters of the display screen according to the state parameters of the background environment on the basis of a preset correspondence relationship, so that the display parameters of the display screen match with the lighting state of the background environment within the viewing angle of the user.