Abstract: Experiments are proposed to study the sound field characteristics of linear ultrasonic phased array with different sound beam steering angles and sound field radius,and compared to the results from the calculation method of phased array sound field based on transient wave displacement analytical solutions.Firstly,the calculation method based on the transient off-plane displacement of semicircle arc is researched,and the accuracy of numerical calculation is optimized.Secondly,an ultrasonic phased array direcvity measurement system are established,semi-circular steel plates are used as the measuring specimens,and the longitudinal wave transducer is used as the measuring transducer.The beam directivity of linear phased arrayis measured at different steering angles (-10°,-30°,-50° and-70°) and sound field radius (50 mm,75 mm,100 mm and 125 mm).Then,the beam directivity of linear phased array is calculated numerically based on the transient wave displacement method with the same sets.Finally,the experimental results are compared with the theoretical results and agrees well with each other.It demonstrates the calculation method of phased array sound field based on transient wave displacement analytical solutions is accurate,as well as for sound beam steering large angles and sound field radius changing.