A manufacturing method of display panels includes providing at least two glass substrates having a predetermined dimension, configuring the glass substrate to be spaced apart from a supporting substrate, forming at least one planarization portion between a gap of the glass substrates and forming a flexible substrate above the planarization portion and the glass substrates, forming a bonding area on the flexible substrate, conducting a cell-formation process or an encapsulation process of the display panel, stripping the supporting substrate, and cutting the flexible substrate via the gap between the glass substrates. In view of the above, the thicker supporting substrate is configured to support the glass substrate so as to avoid two ends of the thinner glass substrate from dropping and curing, which enhances the convenience and the precision of the manufacturing process of the display panel.