The detection device relates to a detection device and detection method for the content of flue gas in asphalt; the detection device comprises a distillation flask; the distillation flask is arranged in an oil bath heater; the distillation flask is connected with a gas outlet pipe; the distillation flask is connected with a sample bottle through the gas outlet pipe; the sample bottle is connected with an activated carbon pipe; the distillation flask is provided with a plug with a stopper; when the device is used, a heat resistant magnetic rotor is put into the distillation flask through a neck mouth. The problems that a conventional asphalt flue gas measurement device has large asphalt use amount, narrow test temperature range, poor temperature control precision, complex composition and operation and the like are solved, so the device has the advantages of small use amount of the sample, high temperature-control range, high temperature-control precision, simple composition, convenience in measurement and the like, and simultaneously obtains the contents of heavy flue gas and light flue gas.