The invention relates to a display device, a display panel and a manufacturing method thereof. The display panel comprises a substrate, a conducting layer, a grid insulating layer, a grid layer, an interlayer dielectric layer and a wiring layer. The conducting layer is arranged on one side of the substrate; the grid insulating layer is arranged on one side, away from the substrate, of the conducting layer; the grid layer is arranged on one side, away from the substrate, of the grid insulating layer; and the thickness of the grid layer is greater than that of the conducting layer. The grid layer comprises a plurality of gate lines. The gate lines form grooves which extend towards the substrate and cut off the gate lines; the grooves are opposite to the conducting layer; and the broken gatelines at the two sides of the grooves penetrate through the grid insulating layer and are connected with the conducting layer. The interlayer dielectric layer is arranged on one side, away from the substrate, of the grid layer, and covers the conducting layer and fills the grooves; the wiring layer is arranged on the side, away from the substrate, of the interlayer dielectric layer; the wiring layer comprises a plurality of auxiliary electrode wires; and the orthographic projections of the auxiliary electrode wires on the grid layer intersect with the gate wires in the grooves, and the orthographic projections of the intersection parts on the grid layer are completely located in the grooves.