A method for manufacturing an array substrate includes (S1) forming a pattern including a gate electrode and a gate line, (S2) forming an insulating layer, (S3) forming a pattern including an active layer, where the region where the active layer is arranged includes a first region corresponding to the gate electrode and second regions arranged on both sides of the first region, (S4) forming a mask pattern including a hollowed-out portion, a first portion and a second portion, wherein the second portion has a thickness smaller than the first portion, (S5) etching the insulating layer to form a via hole for exposing a portion of the gate line, and (S6) ashing a portion of the mask pattern corresponding to the second region to remove the portion of the mask pattern corresponding to the second region, and implanting ions into the active layer.