The invention discloses a sampling device for smoke discharge gas. The sampling device comprises a plurality of sampling pipelines, a mother pipe, a sampling platform, a sampling probe, an air pre-heater and an analyzer, wherein each of the sampling pipelines is respectively provided with a plurality of sampling opening; the sampling pipelines are respectively connected with the mother pipe; the mother pipe is provided with a primary reducing part and a secondary reducing part at the sampling platform, and a buffer tank is formed in the middle part between the primary reducing part and the secondary reducing part; the mother pipe passes through the sampling platform and is connected with the air pre-heater to form a measurement bypass; the sampling probe is located in the buffer tank, and the signal output end of the sampling probe is connected with the analyzer. The sampling device for smoke discharge gas disclosed by the invention can be used for accurately and reliably sampling and measuring the concentration of the smoke discharge gas.