The utility model discloses automatic calibration system of ammonia escape belongs to smoke detection technical field, including ammonia gas detection survey appearance, ammonia standard gas bottle, sampling device, automatic switch -over valve, relief pressure valve and flowmeter, ammonia gas detection surveys the inside singlechip that is provided with of appearance, and the air inlet department that ammonia gas detection surveyed the appearance is provided with the automatic switch -over valve, and wherein the automatic switch -over valve is connected with the singlechip, ammonia standard gas bottle is connected with the automatic switch -over valve through first pipeline, sampling device one end is connected with the flue, and the other end passes through the second pipeline and is connected with the automatic switch -over valve, relief pressure valve and flowmeter are all installed on first pipeline, and relief pressure valve and flowmeter all are connected with the singlechip. The utility model provides an automatic calibration system of ammonia escape, automatic calibration system and ammonia gas detection survey appearance formula structure as an organic whole, survey the appearance to ammonia gas detection and carry out the self -calibration in real -time detection, but continuous monitor has improved the measuring accuracy.