Embodiments of the present invention provide an array substrate and a manufacturing method thereof and a touch display device. The array substrate comprises multiple data lines, multiple gate lines and multiple thin film transistors. The data lines and the gate lines intersect with each other in different planes to divide the array substrate into multiple pixel units, in each of which a thin film transistor is provided, wherein the array substrate further comprises multiple first touch sensing electrodes and multiple second touch sensing electrodes. The first touch sensing electrodes are provided below active regions of the thin film transistors and also serve as metal shielding layers for blocking light emitted by a backlight source. The first touch sensing electrodes and the second touch sensing electrodes intersect with each other in different planes, and capacitances are formed at intersections of the first touch sensing electrodes and the second touch sensing electrodes.