Abstract: On the basis of the study and test of the infrared thermal imager and ultrasonic excitation system at home and abroad, ultrasonic thermal wave detection system was constructed depending on the uncooled focal plane infrared thermal imager and ultrasonic plastic welding machine with high frequency. Through designing reasonable loading device, the ultrasonic gun was realized to incent the structure perpendicular to the measured surface. It ensured that the ultrasonic energy could enter into the measured material effectively. Then the thermal imager was adjusted successfully and was focused in the whole detection surface field through a special transition piece. Industrial aluminum was determined to be used to set up above devices. At the same time, according to the characteristics of ultrasonic thermal wave detection technology, special tools were designed and implemented. Ultimately, experiment was carried out by using the system. The test results show that the controllable performance of the system is good as well as the operation performance which verifies the detection system can satisfy the design requirement.