1. A camera module array comprising: a plurality of lens modules comprising seven lens modules, which are arranged in a regular hexagonal array with one of the lens modules in the middle, each lens module comprising a lens barrel and at least one lens received in the lens barrel; a first holder, the lens barrels of the lens modules being threadedly coupled to the first holder; a plurality of image sensors in optical alignment with the lens modules in one-to-one relation; a second holder, the image sensors being received in the second holder; an optical element sandwiched between the first holder and the second holder, the first holder, the second holder and the optical element each being regular hexagonal in shape; and an image processor electrically connected with the image sensors, the image processor being configured for processing image signals from the image sensors, and, accordingly, obtaining a compound image based on the image signals.