Through P- and S-waves transducers with various vibration characteristics and diameters, the measurement accuracy of huge size samples with different internal structures was studied by three kinds of ultrasonic measurement techniques. The results show that the measurement accuracy of shear-wave velocity is greatly influenced by internal structure of rock samples and measurement methods. Compared with other measurement methods, transmission method can obtain relatively high measurement accuracy of shear-wave velocity, and important information relative to anisotropy and heterogeneity of rock samples is also contained in the measurement process.