The invention provides an array substrate, a preparation method thereof and a liquid crystal display panel, belongs to the field of display technology, and aims to solve the problem of relatively large thickness of a product due to light leakage of an independent backlight source outside an existing liquid crystal display device. A light-emitting structure and an array structure are simultaneouslyarranged on the array substrate, wherein a control component of the light-emitting structure can control a light-emitting source to emit light. The light-emitting structure is formed directly on thearray substrate, namely, the light-emitting source is built in, so that bonding with an external backlight source is not needed anymore; light leakage caused by bonding gaps is avoided; and the thickness of the product can be reduced.