The present invention provides an array substrate and a manufacturing method thereof, and a display apparatus; and it relates to the field of display. The array substrate includes a first thin film transistor and a first electrode which are formed on a substrate. The first thin film transistor includes a gate, a gate insulating layer, an active layer, and an etch stop layer. The etch stop layer is formed with first via holes, and the etch stop layer and the gate insulating layer are formed with a second via hole at a position corresponding to the first electrode. A maximal diameter of the first via holes is not greater than a minimal diameter of the second via hole.