The utility model belongs to the technical field of environment monitoring technology and specifically relates to a pollution sources waste gas composite sampling system is related to. This composite sampling system, including the sampling rifle that is used for gathering the sample, with terminal fixed heating cabinet and the water bath of sampling rifle, be equipped with the sampling pipe in the sampling rifle, the end of giving vent to anger of sampling pipe stretch into in the heating cabinet with the heating cabinet in the air inlet intercommunication of three -way valve, a gas outlet of three -way valve communicates with the air inlet that the interior filter membrane of heating cabinet pressed from both sides, parallelly connected two sets of impacted style absorption bottles, the air inlet of a set of impacted style absorption bottle and another gas outlet intercommunication of three -way valve of being equipped with in the water bath, the air inlet of a set of impacted style absorption bottle communicates with the gas outlet that the filter membrane pressed from both sides in addition. The utility model discloses a set up the three -way valve in the heating cabinet, a sampling branch road is connected respectively to two exit ends of three -way valve, makes the utility model discloses can be used for the sample of multiple waste gas, through device control ware and display in the heating cabinet, can realize the real time monitoring to the sample process.