The present disclosure provides an array substrate, a manufacturing method of the array substrate, and a display device. The array substrate includes a hydrogen ion film formed between an active layer and a source/drain electrode of a low temperature poly-silicon thin film transistor, and a hole is formed in a region of the hydrogen ion film where a metal-oxide-semiconductor thin film transistor is disposed. Based on the hydrogen ion film, the electrical performance and stability of the low temperature poly-silicon thin film transistor are improved. Furthermore, hydrogen elements are not diffused to the region where the metal-oxide-semiconductor thin film transistor is disposed.