An anti-lock brake apparatus, a vehicle, an electric vehicle and an electric-assisted vehicle. The anti-lock brake apparatus is applied to a brake system, and the brake system is used to provide a brake frictional force for a wheel, the brake system includes a brake oil pipeline, and the anti-lock brake apparatus includes: a volume-adjusting part, the volume-adjusting part has a volume chamber, the volume chamber is connected into the brake oil pipeline, a volume of the volume chamber is continuously adjustable, the volume-adjusting part adjusts the volume of the volume chamber according to a state parameter of the wheel, to enable an oil pressure in the brake oil pipeline to vary, and the brake frictional force exerted on the wheel by the brake system is adjustable. The apparatus has high reliability and high brake efficiency.