The invention provides a full-fraction FCC (fluid catalytic cracking) gasoline alkadiene removal/super deep desulfurization composite treatment method which comprises the following steps: I, enabling full-fraction FCC gasoline and hydrogen as raw materials to contact a alkadiene removal catalyst so as to remove alkadiene in the full-fraction FCC gasoline; II, performing fractionation so as to form a heavy component and a light component; III, performing hydrodesulfurization on the heavy component so as to obtain a low-sulfur heavy component; performing hydrogening adsorption desulfuration on the light component so as to obtain a low-sulfur light component; IV, mixing the low-sulfur heavy component with the low-sulfur light component, thereby obtaining super low-sulfur gasoline of which the sulfur content is less than 10ppmw. As the full-fraction FCC gasoline is subjected to selective hydrogenation to remove alkadiene, and composite treatment for super deep desulfurization is implemented with the combination of techniques of hydrodesulfurization and hydrogening adsorption desulfuration, the sulfur in the full-fraction FCC gasoline can be reduced to be less than 10ppmw, the octane value loss is less than 2 units, and the liquid yield is greater than 99.8%.