Taking the manufacture of a flexible display substrate including a flexible substrate as an example, the flexible substrate is formed on a support plate at first, and then a plurality of display devices is formed simultaneously, and arranged on the flexible substrate with high utilization rate, so as to form a flexible display substrate motherboard. Next, the flexible substrate is separated from the support plate through a laser lift off (LLO) process or any other appropriate separation process, a base layer is attached onto a surface of the flexible substrate away from the display element, and then a slicing process is performed so as to obtain flexible display substrates separated from each other. Usually, a cutting region between two adjacent display devices on the flexible display substrate motherboard is cut through a laser cutting process. However, due to a relatively high temperature of the laser cutting, usually a laser cutting operation is performed with certain distance from an edge of the display device, so as to prevent the display device from being adversely affected by the high temperature. In other words, it is necessary to provide a cutting margin for the laser cutting process. However, reserving the cutting margin is adverse to the design of an ultra-narrow bezel. Hence, through the conventional cutting method for the display device, it is impossible to provide the ultra-narrow bezel while ensuring the quality of the display device.