TFT array substrate, display panel and manufacturing method of display panel

The invention discloses a thin film transistor array substrate. The TFT array substrate comprises a gate metal layer, a gate insulating layer, a semiconductor layer, a source/drain metal layer, a planar layer, a first protection layer, a first electrode layer, a second protection layer and a second electrode layer, wherein the first electrode layer comprises pixel electrodes, the second electrode layer comprises public electrodes, communicating holes are formed in the planar layer, and the pixel electrodes make contact with the drain metal layer through the communicating holes. The invention further provides a display panel and a manufacturing method of the display panel. According to the manufacturing method, etching is performed on the first protection layer with the planar layer as a light shielding cover to form the communicating holes penetrating through the first protection layer and the planar layer so that the pixel electrodes can make contact with the drain metal layer through the communicating holes, the occupied area of the communicating holes is reduced, and thus the requirement for a high aperture rate can be met; besides, the communicating holes are only formed in the process of one light cover, and thus the manufacturing cost and the complexity of the technology are reduced.