A light emitting diode and a driving method thereof, a light source apparatus, and an electronic device are disclosed, relating to the technical field of semiconductors. The light emitting diode includes: a substrate; a reflective light-emitting layer disposed on the substrate; a first electrode, a second electrode, and a first insulating layer which are discretely disposed on the reflective light-emitting layer; a saturable absorber layer disposed on the first insulating layer; and a third electrode, a fourth electrode, and a reflective composite layer which are disposed on the saturable absorber layer, respectively, the reflectivity of the reflective light-emitting layer is greater than the reflectivity of the reflective composite layer; wherein the orthographic projections of the saturable absorber layer, the third electrode, the fourth electrode, and the reflective composite layer on the reflective light-emitting layer, respectively, do not overlap with the first electrode and the second electrode.