An array substrate, manufacturing method thereof, and a display device according to some arrangements of the present disclosure include: a first transistor and a second transistor; an active layer of the second transistor is disposed on a side of the interlayer dielectric layer of the first transistor away from the substrate; an insulating layer is disposed between the interlayer dielectric layer of the first transistor and the active layer of the second transistor, and the insulating layer has an ability to block hydrogen.