One or more embodiments of the description relate to a flexible display device and a display system. The flexible display device includes: a display screen body; a functional auxiliary structure connected to the display screen body to provide isolation in case that the display screen body curls up and/or support in case that the display screen body is unfolded. The functional auxiliary structure includes an isolation component and/or a support component. The support component is capable of isolating at least a part of the display screen body in a curled state; the support component is capable of providing support for the display screen body in an unfolded state.