The invention discloses a fast mounting component for an outer wall decoration board and aims to solve the problem that a metal curtain wall is low in mounting efficiency in the prior art. The fast mounting component comprises a U-shaped connector, a support column and double-end nuts and is characterized in that the ends of two vertical sections of the connector extends outwardly to form extended sections parallel with the horizontal section of the connector, two through holes are formed in the horizontal section of the connector, the inner diameter of each through hole gradually decreases along a direction from the inner lateral wall of the horizontal section of the connector to the outer lateral wall of the horizontal section, a screw movably penetrates each through hole and provided with a protrusion matched with the through hole, the support column is connected with the outer lateral wall of the horizontal connector of the connector through a pin, and each double-end nut sleeves the corresponding screw. The fast mounting component has the advantages that by the coordination of multiple mounting components during mounting, the mounting time of the single board is shortened, the work intensity of mounting staff is lowered at the same time, and the mounting efficiency of the metal curtain wall is increased.