The invention discloses a high-frequency ultrasonic transducer made of a piezoelectric monocrystalline composite material as well as a manufacturing method and an application thereof. The high-frequency ultrasonic transducer consists of a piezoelectric monocrystalline composite material wafer, a damping backing material, a first matching layer, a second matching layer, a coaxial electrode lead, a coaxial connector and a metal shell, wherein the second matching layer, the first matching layer, the piezoelectric monocrystalline composite material wafer and the damping backing material are bonded together in sequence; and the coaxial electrode lead is introduced from the positive electrode and the negative electrode of the piezoelectric monocrystalline composite material wafer to the coaxial connector which is fixed on the metal shell. The invention provides a method for manufacturing the transducer by matching acoustic characteristic based on a KLM model. The center frequency Fc of the obtained ultrasonic transducer is equal to 14.67MH, the bandwidth Bw can be up to 107 percent and the pulse echo sensitivity Sr can reach -30dB; and the ultrasonic transducer also has very high sensitivity on the premises of high frequency and large bandwidth. The ultrasonic transducer can be used for medical diagnosis, ultrasonic nondestructive detection and precise thickness measurement.