A brief account of the basic reaction principles of reducing olefin contents in FCC gasoline was introduced and the measures of reducing olefin were discussed. To the problem of redundant olefin fraction of gasoline, which is attributed to the high proportion of FCC gasoline with ample olefins in gasoline pool, adjusting and optimizing the technology of FCC, employing new reducing olefin catalysts are put forward. In order to solve the problem completely, the structure of gasoline production should be adjusted, such as building the more units for catalytic reforming, alkylation,isomerization and decreasing the ratio of FCC gasoline.