Disclosed are a display substrate, a manufacturing method thereof, a display panel and a display device. The display panel comprises: a base substrate provided with a first area and a second area which are not overlapped with each other; a low temperature poly-silicon transistor arranged in the first area, the low temperature poly-silicon transistor comprises a poly-silicon active layer; an oxide transistor arranged in the second area, the oxide transistor comprises a first gate electrode; the first gate electrode is arranged in a same layer as the poly-silicon active layer, and a material of the first gate electrode is heavily-doped poly-silicon.