Abstract: Total focusing phased array is a hot topic in ultrasonic nondestructive testing. However, its acoustic characteristics and testing process are rarely reported. Based on the CIVA simulation software platform, the acoustic field simulation and defect response of total focusing phased array are studied in this paper. Using the same excitation parameters and probe aperture to simulate the conventional ultrasonic sound field and the total focusing phased array sound field, the characteristics of each sound field are analyzed and compared. The impact between the sound field and the transverse hole of the total focusing phased array is simulated by the defect response simulation, and the detection ability of the total focusing phased array technique is analyzed. The research work of this paper provides an reference for the R & D design and testing process of total focusing phased array probe.