The present invention discloses a flexible substrate and a manufacturing method thereof, and a display device, comprising: disposing a detachable layer on a rigid substrate, and fixing the flexible base on the rigid substrate by the detachable layer, wherein the detachable layer comprises a mesh layer and a plurality of mutually independent supporting parts disposed in meshes of the mesh layer; forming a functional layer on the flexible base to obtain a flexible substrate; separating the flexible substrate from the rigid substrate by applying an external force on the mesh layer. The present invention makes it easier for the flexible substrate to be stripped off after it is manufactured, improves the yield rate; moreover, the present invention has the process compatibility of ordinary production lines, and saves costs.