The present invention provides a display substrate and a manufacturing method thereof, and a flexible display device including the display substrate, which belong to the field of display technology, and can solve the problem of poor reliability of an existing display substrate due to damage to thin film transistors when the display substrate is bent. In the display substrate provided by the present invention, by providing the stress absorbing units made of a resin material in the display substrate, the stress generated during bending of the display substrate is released through the transparent resin material and the thin film transistors on the display substrate are unlikely to be damaged, thereby improving the reliability of the whole display substrate.