Adapter assembly, wiper blade assembly, windscreen wiper and vehicle

The utility model discloses an adapter assembly, a wiper blade assembly, a windscreen wiper and a vehicle. The adapter assembly is used for being detachably connected with a wiper rod of a windscreen wiper of a vehicle, the wiper rod comprises a wiper rod first end and a wiper rod second end which are arranged in the length direction, the wiper rod second end is used for being connected with the vehicle, and the wiper rod first end is provided with a wiper rod notch. The adapter assembly includes an adapter and a retaining element. The adapter is suitable for being detachably connected with the first end of the wiper rod, and the adapter comprises an adapter notch suitable for being aligned with the wiper rod notch; the retaining element is connected with the adapter, a retaining element protrusion is arranged on the side, facing the adapter, of the retaining element, and the retaining element protrusion is suitable for being contained in the wiper rod notch and the adapter notch at the same time. According to the invention, when the wiper rod gap and the adapter gap are not aligned, the retaining element projection cannot enter the wiper rod gap, and a user is prompted of an assembly error.