An array substrate, a display panel and a manufacturing method thereof are provided. The array substrate includes a base substrate including a peripheral region; and a lead region located in the peripheral region, the lead region including a plurality of leads, wherein a main plane of the base substrate provided with the plurality of leads includes a first side edge, and the plurality of leads extend to the first side edge, a lateral surface of the base substrate at the first side edge is provided with a concave portion, and an electrode electrically connected with the plurality of leads is disposed in the concave portion.