Based on a new laser interferometer, the vibration state of transducer surface is measured and analyzed. The vibration waveforms of each point on the two-dimensional surface of the transducer are obtained by using a multi-channel detection unit laser interferometer. Three transducers (the center frequencies are 2.25, 5, 10 MHz) with large differences in performance are compared subsequently. According to the measured surface vibration waveform of transducer, the echo signal in ultrasonic testing is quantitatively calculated by finite element method, and the calculated results are compared with the experimental results. The results show that the laser interferometer can directly and quantitatively characterize the surface vibration state of ultrasonic transducer, and can clearly distinguish the working performance difference of ultrasonic transducer. The measurement results have a good application value for evaluating the performance of ultrasonic transducer and predicting the echo signal of ultrasonic testing.