An array substrate and a manufacturing method thereof, and a display device are provided. The array substrate includes: a base substrate, and a GOA circuit, a source electrode IC and PLG wires arranged on the base substrate, and the PLG wires connect the GOA circuit with the source electrode IC. The GOA circuit transmits a GOA signal, and the GOA signal comprises a cascade signal and a non-cascade signal. The PLG wires comprise a first PLG wire group and at least one second PLG wire group, the first PLG wire group transmits the cascade signal, the second PLG wire group transmits the non-cascade signal, a line width of the first PLG wire group is smaller than that of the second PLG wire group, and the first PLG wire group is located at a side of the second PLG wire group distal to an active area of the base substrate.