The instrument for determination of fluorine and chlorine in coal and other combustible matter is used for heat-engine plants, coal mine, steel mills and petroleum and chemical industry. Until now the instrument for determination of fluorine and chlorine has not had relevant verification regulations or calibration specifications. This paper proposed easy and reliable calibration methods according to the apparatus structure and operational principle, calibrating the temperature control performance and measurement performance. And the calibration results have favorable traceability and comparability.