Abstract: The present disclosure relates to a thin film transistor (TFT) substrate, a manufacturing method thereof, and an organic light-emitting (OLED) substrate. The interlayer dielectric layer manufactured by the manufacturing method may be configured in the structure of two silicon oxide layers sandwiching one silicon nitride layer. As such, the bonding force between the interlayer dielectric layer and the gate, and the bonding force between the interlayer dielectric layer, and the source and the drain may be improved. The source and the drain may be prevented from falling off from the interlayer dielectric layer during the annealing process. Production yield of the TFT substrate may be improved. The OLED substrate adopting the manufactured of the OLED substrate of the present disclosure may have a better production yield and quality.