The present disclosure relates to a chassis and a heat sink for use in the chassis. Disks in rows are arranged in the chassis, and the heat sink comprises an air ingress channel extending from a first end of a housing of the chassis to a side portion of the disks away from the first end; an air egress channel extending from the first end to a second end opposite to the first end, the air egress channel being spaced apart from the air ingress channel by the disks; an intermediate channel comprised of gaps between the disks and fluidically communicating the air ingress channel with the air egress channel; and a fan disposed in the air egress channel and being operable to form a negative pressure in the air egress channel.