Abstract: A pulse compression system in non-destructive testing, which consists of linear frequency modulated pulse signal and digital Matched filter using digital electric exciting signal, is presented. Ultrasonic pulse compression signal is obtained in various time bandwidth products systems. Experimental results are in fine agreement with the theory. The reduction of sidelobe of -41.9 dB and -41.5 dB can be achieved for Hamming and Gaussiau weighed signal. The performance of ultrasonic detecting system will be improved greatly by using digital matched filter technique.