1. A camera module, comprising: a lens group; an image sensor; and a liquid crystal module disposed between the lens group and the image sensor, the liquid crystal module comprising a first glass substrate adjacent to the image sensor, an opposite second glass substrate, a plurality of liquid crystal molecules arranged between the first glass substrate and the second glass substrate, a first transparent electrode layer formed on the first glass substrate and facing the liquid crystal molecules, and a second transparent electrode layer formed on the second glass substrate and facing the liquid crystal molecules, the liquid crystal molecules being configured for adjusting light path of the light transmitting therethrough in response to an electric field between the first and second transparent electrode layers, thus adjusting depth of field of the camera module.