A display panel, a display apparatus and a control method therefor. The electrode group included in the display panel is used for controlling, when loaded with a voltage, the refractive index of the liquid crystal layer, such that when the refractive index of the liquid crystal layer is less than the refractive index of the first substrate, light emitted by the light-emitting module is propagated by means of total reflection in the first substrate, and when the refractive index of the liquid crystal layer is greater than the refractive index of the first substrate, the light emitted by the light-emitting module is propagated toward the second substrate from the first substrate.