The invention discloses a brake disc. The brake disc comprises two disc bodies connected through a connecting rib, wherein space between the two disc bodies forms an air flow channel, each disc body is provided with a disc surface connected with the connecting rib, and the disc surface of at least one disc body is wave-shaped. The disc surface of at least one disc body is wave-shaped, so that the wave-shaped air flow channel is formed between the two disc bodies, air flow can tumble in the wave-shaped air flow channel when passing through the brake disc and certain acceleration can be formed, the contact area of the air flow with the disc bodies is increased, the retention time of the air flow in the channel is prolonged, the flow velocity of the air flow is increased, accordingly, the air flow is heated sufficiently, and the heat dissipation effect of the brake disc is improved. Meanwhile, the wave-shaped disc body facilitates resistance of radial growth of cracks, and the service life of the brake disc is prolonged effectively. When the disc surfaces of the two disc bodies are both wave-shaped and crests and troughs of the two disc surfaces are arranged correspondingly, the liquidity of the air flow is better.