Abstract: The change of inside temperature of tunnel engineering is very small all the year round,the temperature of background outside the tunnel engineering affected by manifold factors such as illumination,lapse rate and heat exchange changes greatly all the year round and one day,so the infrared characteristic of tunnel engineering gateway becomes complexity,single means can hardly simulate accurately and momentarily. A intelligentized infrared decoy control system is designed by singlechip,temperature sensor and solid relay,it has the advantages of good decoy effect,high informationization and controlling in real time,the system is proved by the field test that running is steady and it can simulate the typical infrared characteristic of tunnel engineering gateway in different period of time,it offers a available technique for controlling the infrared decoy of engineering gateway in real time.