Based on the needs of ultrasonic nondestructive testing technology, a method for exciting the frequency-mixing surface acoustic waves based on the theoretical analysis of the frequency-mixing effects of surface acoustics waves is proposed in this paper, and the corresponding experimental observation of frequency-mixing harmonic of surface acoustic waves is carried out. A wedge transducer consisting of a transverse transducer and a longitudinal one is designed and fabricated to excite the mixing surface acoustic waves induced by the oblique incidence of a bulk transverse wave and a bulk longitudinal one. By choosing appropriate cycle number and time delay of the transverse and longitudinal wave excitation signals, the surface acoustic waves excited by the oblique incident bulk transverse and longitudinal waves can be completely mixed. By performing pulse inversion processing and Fourier transform on the received time-domain signals, the apparent surface acoustic wave mixing harmonic signals can be obtained. The results show that the mixed-frequency surface waves can be effectively generated with the help of the oblique incident transverse and longitudinal waves passing through the wedge, and the experimental observation is consistent with the theoretical expectation, which lays a foundation for the development of ultrasonic non-destructive testing technique based on the mixing surface acoustic waves.