Abstract: TMCP steel is characteristic of high strength and high toughness and is often used to make thick steel plates. The TMCP steel presents anisotropy. The ultrasonic wave has different sound velocity and refractive angle between steel plate rolling direction and the vertical rolling direction. The experiment to study the influence of anisotropy of TMCP steel on the angle of refraction of ultrasonic wave was designed and carried out. The experimental results have shown the variation of the angle of refraction with TMCP steel rolling direction and thickness, which provides reference for TMCP steel ultrasonic testing.