The present disclosure provides a touch display panel, a flexible display panel and a display apparatus. In one embodiment, light sensitive effect-based photo-sensitive diodes and switching transistors for controlling signal output of the photo-sensitive diodes are integrated in the display panel. Once a touch operation of an object (e.g., a finger) is implemented on a surface of the display panel, the photo-sensitive diode in a corresponding position can convert a sensed light intensity difference into an electrical signal difference to achieve detection of the touch operation.