The invention provides a display panel, a control method of the display panel, and a display device. According to the display panel, the control method of the display panel, and the display device, adisplay status or a non-display status is realized by adjusting the refractive index of a refractive layer, the light-emitting efficiency of the display panel is adjusted by forming a grating structure whose refractive index changes periodically in the display stage, and thus gray scale display is realized, that is, the gray scale display of the display panel does not need to be provided with a polarizer, and the transmittance and transparency of a display product can be improved through the display panel; and ambient light can penetrate through the display panel to realize transparent display, a transparent area is not needed to be divided in a display area separately, the resolution of the display device cannot be affected, and the design of the display device with high PPI is facilitated.