Disclosed are a display panel, a manufacturing method thereof, and a display device. The display panel includes a base substrate and sub-pixels thereon. At least one sub-pixel includes: a light emitting element including a first electrode, a luminous functional layer and a second electrode sequentially stacked, the first electrode being closer to the base substrate than the second electrode; a metal reflective layer, between the base substrate and the first electrode; a silicon nitride layer, between the first electrode and the metal reflective layer, and including a first via hole through which the first electrode is connected with the metal reflective layer; a driving circuit including a driving transistor and a storage capacitor between the base substrate and the metal reflective layer, the driving transistor including a gate electrode connected with the storage capacitor, and source and drain electrodes, one of which is connected with the metal reflective layer.