Method and device for displaying camera preview pictures as well as terminal

The invention is suitable for the technical field of the terminals and provides a method and a device for displaying camera preview pictures as well as a terminal. The method comprises the following steps: transmitting a picture shot by a first camera to the display screen of the terminal in real time as a first preview picture; detecting a focused object in the preview picture; zooming a second camera to the region of the focused object and generating a second preview picture according to a picture shot by the second camera in real time; synthesizing the second preview picture with the specified pixel region of the first preview picture and simultaneously displaying the preview pictures on the display screen of the terminal. According to the method for displaying the camera preview pictures, a picture-in-picture effect can be shown on the display screen of the terminal in the shooting process, the whole shooting scene and the focused object are displayed simultaneously and the detailed preview of the focused object is realized; as a result, a picture poor in focused object display is prevented and the waste of time and system resources is avoided.