The invention relates to an externally-heating vertical type active carbon activating furnace. The lower end of an outer cylinder (13) of the activating furnace is driven to rotate by a motor; a heating passage (14) is arranged between the outer side of the outer cylinder (13) and a furnace wall (15); a heating plate (3) of the outer cylinder and a heating plate (6) of an inner cylinder are sequentially and alternately arranged in the axial direction; a shovelling plate (4) of the outer cylinder and a shovelling plate (5) of the inner cylinder are respectively arranged on the lower sides of the heating plate (3) of the outer cylinder and the heating plate (6) of the inner cylinder respectively through hinges and are spirally distributed; a gas division pipe (7) is extended to the lower side of the heating plate (6) of the inner cylinder; gas division pylomes are distributed on the lower side of the heating plate (6) of the inner cylinder; and the sidewall of the inner cylinder (16) corresponding to a burning chamber (1) is provided with a gas outlet (17). The externally-heating vertical type active carbon activating furnace has a compact structure, and can continuously produce active carbon from various raw materials; and the active carbon has high yield, quality, strength and surface glossiness; and the activating furnace has long service life.