Abstract: A TFT substrate and a manufacturing method thereof, a liquid crystal display panel and an OLED display panel are provided. The TFT substrate provided by the embodiment of the present application is obtained by setting the source electrode and the drain electrode to be etched from a conductive layer, the conductive layer includes a first metal layer and a second metal layer that are stacked and arranged, and the standard electrode potential of the first metal layer is set to be lower than the standard electrode potential of the second metal layer, the thickness of the first metal layer is set to 50?˜150?, which is beneficial to make the etched source and drain electrodes have smaller taper angles.