Under the loading of nanosecond laser pulse, a surface wave ultrasonic velocity measurement technology for non-specular surface metal sample based on Michelson interferometer system is developed. In order to obtain characterful singal of surface wave, the convergent reflection signal light from non-specular surface of tantalum slice interferes with attenuating reference light. In the interference intensity change history, distinct characteristic signal of surface wave can be inspected. Through the result of arrival time of different detection points and linear fitting method, surface wave of tantalum is successfully measured. A result of transverse wave velocity comparable to the reported one is obtained based on the measured surface wave ultrasonic velocity.