The invention discloses a display panel, a display device and a display method thereof. The display panel comprises a substrate, an organic light-emitting device layer, a detection sensor and a colorswitchable structure, wherein the organic light-emitting device layer, the detection sensor and the color switchable structure are sequentially located on the substrate and are insulated from one another. The organic light-emitting device layer comprises a plurality of sub-pixels, and the color switchable structure comprises sub-units arranged in one-to-one correspondence with the sub-pixels; eachsubunit is used for transmitting light emitted by each sub-pixel under the control of the applied different signals, or displaying light of a color corresponding to the applied signals; the detectionsensor is configured to detect a display parameter of each sub-pixel or each sub-unit. According to the display panel of the structure, each sub-pixel in the organic light-emitting device layer can be firstly controlled to be lightened; when the detection sensor detects that the first display parameters of the sub-pixels do not meet a first display condition, all the sub-units in the color switchable structure are controlled to conduct display, thereby achieving the purpose of prolonging the service life of the display panel.