A display panel and a manufacturing method thereof are provided. The display panel comprises a glass substrate, an insulating layer, a polysilicon layer, a gate insulating layer, a gate layer, an interlayer insulating layer, and a source-drain contacting layer, wherein the polysilicon layer is defined with a first doped region, a second doped region, and a third doped region. The source-drain contacting layer contacts the first doped region and the third doped region. A doping type of the first doped region and a doping type of the third doped region are different so that the first doped region and the third doped region form a PN structure. Doping type of the first doped region and a doping type of the second doped region are same.