Device capable of improving low emission performance of gas turbine and use method

The invention discloses a device capable of improving the low emission performance of a gas turbine and a using method, and is applied to the technical field of gas turbine emission control. By arranging a pretreatment assembly, discharged flue gas can be pretreated conveniently, so that particulate matter in the flue gas is reduced, and the emission performance of the gas turbine is improved; when the structure is used, smoke of a combustion chamber is introduced into the structure through the smoke inlet pipe, the smoke passes through the filter screen outside the net rack when passing through the structure, particulate matter in the smoke is filtered out, the filter screen can be taken down along the net rack during maintenance so as to be replaced conveniently, and then the adjusting valve can be selectively opened to enable part of the smoke to enter the circulating pipe, so that the smoke can be recycled. The flue gas is pumped into the auxiliary section through the flue gas pump and is output back to t