Embodiments of the present disclosure provide a flexible display screen and a flexible display device. The flexible display screen includes a display screen body and a deformation component disposed on a back side of the display screen body, wherein when an ambient temperature is higher than a first temperature threshold value, the deformation component is deformed towards a direction in which the display screen body reveals curved display; when the ambient temperature is lower than a second temperature threshold value, the deformation component is deformed towards a direction in which the display screen body reveals flat display; and the second temperature threshold value is not greater than the first temperature threshold value.