The invention provides a broadband transducer and a preparation method thereof. The broadband transducer comprises a potting material (1), a piezoelectric material (2), a filling material (3), a backing material (4), a transducer base (5) and a cable (6), the piezoelectric material (2) comprises an array columns arranged on the bottom surface and the bottom surface, the filling material (3) fillsthe space between the array columns of the piezoelectric materials(2), the bottom surface of the piezoelectric material (2) serves as a radiating surface, the radiating surface of the piezoelectric material (2) is arranged on the backing material (4) outwards, the backing material (4) is connected with the transducer base (5), the cable (6) is connected with a positive electrode and a negative electrode of the piezoelectric material (2), the potting material (1) is used for encapsulating the connected piezoelectric material (2), the filling material (3), the backing material (4) and the transducer base (5). According to the method, the mode that the piezoelectric material is used for cutting and reserving the bottom is adopted, the bottom surface serves as the radiating surface, the effective radiation resistance of the transducer is increased, and the bandwidth and the receiving sensitivity of the transducer are improved.