Aiming at the impedance mismatch between the piezoelectric ultrasonic transducer and the excitation source in the rail damage detection system, as well as the resonant frequency shift of the piezoelectric ultrasonic transducer after loading, this paper studies the broadband impedance matching of the piezoelectric ultrasonic transducer. Firstly, the parameters of the piezoelectric ultrasonic transducer BVD model are optimized. Secondly, four matching networks are designed based on the above models, and their performances are compared and analyzed to determine the optimal network topology and parameters. Finally, based on experimental platform of pitch-catch, the received signals of piezoelectric ultrasonic transducers before and after matching are tested and compared. The test results show that the impedance matching network designed in this paper can achieve efficient matching of piezoelectric ultrasonic transducers, and the active power of the transmitter transducer is increased by an average of 197.38% after matching, and the operating bandwidth is increased from 1.44 kHz to 2.22 kHz. Compared with the unmatched and traditional L-shaped matching network, the broadband impedance matching network designed in this paper increases the emission intensity by 61.07% and 18.05% respectively, and the piezoelectric ultrasonic transducer can achieve a good working condition within the working bandwidth.