Thin film transistor array substrate, manufacturing method thereof, and display device

The invention relates to the display technology field, and discloses a thin film transistor array substrate, a manufacturing method thereof, and a display device. The metal conductive layer surface in a non-display region of the array substrate is covered with an antioxidant structure so as to prevent the metal conductive layer from being oxidized. Thus, when the metal conductive layer is exposed in the environment, a thin film pattern only located in a display region is formed, the antioxidant structure can protect the metal conductive layer from being oxidized, transmission resistance of the metal conductive layer is reduced, features of electrical contact between the metal conductive layer and a subsequently-formed conductive layer are improved, and the quality of the array substrate is improved.