The present invention provides a TFT array substrate, a manufacturing method thereof, and a display panel thereof, wherein the thin-film transistor (TFT) array substrate is defined with a first area and a second area, and includes a substrate layer, wherein a first TFT is disposed on the substrate layer in the first area, and a second TFT is disposed on the substrate layer in the second area; and wherein the first TFT is a top-gate TFT, the second TFT is a bottom-gate TFT, and a material used for a source/drain layer of the first TFT is same as a material used for a gate layer of the second TFT. The present invention provides a TFT array substrate, which adopts a novel film structure design, so that a low temperature poly-silicon (LTPS) TFT and Oxide TFT provided thereon can have great compatibility in the design and manufacturing process.