The invention provides a method for patterning a flexible substrate. The method for patterning a flexible substrate includes providing a carrier substrate. A release layer is formed on the carrier substrate. A flexible substrate film is formed on the release layer. A plurality of UV blocking mask patterns is formed covering various portions of the flexible substrate film and the release layer. A UV lighting process is performed to expose the flexible substrate film and the release layer not covered by the UV blocking mask patterns, to a UV light. A debonding step is performed so that the various portions of the flexible substrate film directly above the various portions of the release layer, which were not exposed to the UV light, are separated from the carrier substrate.