The invention discloses a low-concentration 
smoke dust sampling device. The low-concentration 
smoke dust sampling device comprises a main 
machine, a sampling gun, a condenser and a drier. The sampling gun comprises a 
handle, a sampling tube, a pitot tube and a 
thermocouple, wherein the sampling tube, the pitot tube and the 
thermocouple are connected with the 
handle. The gas outlet end of the sampling tube is sequentially connected with the condenser, the drier and the main 
machine. The 
thermocouple and the pitot tube are connected with the main 
machine. A multi-stage sampling head is installed at the head of the sampling tube. A sampling 
nozzle is arranged at the front end of the multi-stage sampling head. The multi-stage sampling head comprises a shell and three dust collection units arranged in the shell. The dust collection units are sequentially arranged in the flowing direction of 
smoke. The smoke entering the sampling tube is sequentially in contact with the dust collection units, smoke dust is adsorbed by the dust collection units, and the smoke dust collecting efficiency of the device is improved. The invention further discloses a low-concentration smoke dust sampling method in which the device is adopted. By means of the low-concentration smoke dust sampling device and method, the concentration of the smoke dust is accurately measured under the low-concentration and high-
humidity working condition.