The catalyst for directly preparing high-grade gasoline and diesel oil clean liquid fuel by using synthetic gas and utilizing Fischer-Tropsch synthesis reaction is formed from three portions of active component, adjuvant and carrier, in which its active component is metal iron, the adjuvant is formed from metal elements of Cu, Ce, K, Co and Ru, etc. and its carrier can use apricot stone activatedcarbon or coconut activated carbon, the specific surface area of active carbon is 200 sq.m/g-2000 sq.m/g, its pore volume is 0.3-1.5 cu.cm/g, pore size distribution is 4-1000 A, the metal iron content is 4-40% of total weight of catalyst, the adjuvant element content is 0.01-20.0% of total weight of the catalyst. The addition of adjuvant element can effectively improve the reaction and stability property of catalyst.