The present application provides an array substrate and a manufacturing method thereof. The array substrate includes a thin film transistor and a storage capacitor prepared on a substrate; the thin film transistor includes a gate, an active layer, and a source/drain; the storage capacitor includes a first electrode and a second electrode isolated therefrom by a dielectric layer; the gate is disposed above the first electrode and located at one end of the first electrode; and the second electrode corresponds to a portion of the first electrode non-corresponding to the gate.