The invention provides a flexible display panel making method. A groove is formed in a rigid substrate, a flexible substrate is formed in the groove, a display device layer is made on the flexible substrate and the rigid substrate, a flexible display motherboard is obtained, a common cutter wheel is then adopted to cut the flexible display motherboard along the edge of the groove, a flexible substrate unit is obtained, and the rigid substrate in the flexible substrate unit is peeled through laser to obtain a flexible display panel. In the method, the purchasing cost of a laser cutting device is saved, the flexible display panel making cost is thus reduced, the flexible display motherboard cutting yield by adopting the common cutter wheel is also improved, and the service life of the cutter wheel for cutting the flexible display motherboard is improved, and besides, the use amount of an organic material for making the flexible substrate is also reduced, and the production cost is further reduced.