The invention relates to an integrated device and a process for selective desulfurization and denitrification of flue gas. The device comprises a main column and a vice column arranged on one side ofthe main column, which are respectively used for photocatalytic/H2O2 synergistic oxidation selective photocatalytic denitration and dynamic wave selective alkali washing desulfurization. The flue gasis firstly introduced into the vice column from top to bottom and then selectively washed with alkali and desulfurized through a primary dynamic wave nozzle and a secondary dynamic wave nozzle, coagulated mist is removed by a demister, then the flue gas enters the main column, the desulfurized liquid falls under the gravity and finally flows into a desulfurized liquid storage tank at the bottom ofthe main column, the flue gas flows through a hollow denitrified liquid storage tank and a diversion umbrella from bottom to top in the main column and enters a photocatalytic/H2O2 synergistic oxidation selective denitration zone, and the clean flue gas is discharged from the top of the column. The device is simple in process flow, occupies a small space, and can realize selective desulfurizationand denitrification in one column. The desulfurization and denitration products can also be separately collected, so that the market value of the desulfurization and denitration products is greatly increased.