A systematic study with the aim to reduce NO/NO 2 , SO 2 and to destroy VOCs and PCDD/F in flue gas by electrical discharge both in laboratory and at a pilot plant has been performed. Results show that 1) both indirect and direct treatment by electrical discharge can reduce NO/NO2 and SO2 and can destroy PCDD/F in flue gas; 2) Indirect treatment destroys about 90% of PCDD/F in real industrial flue gas; and 3) It is possible to destroy NO/NO2, SO2 and PCDD/F in one step.