Ultrasonic non-destructive and imaging testing using the line array method is conducted on titanium alloy bars and the sound field distribution of linear array transducer probes is simulated and analyzed. The simulation of the sound field distribution of titanium alloy bars with different diameters is performed by CIVA software. CIVA is used for sensitivity and parametric studies and it can quantify the response to expected defects and can perform different inspection strategies. In this study, the different diameter bars and various defects are simulated by considering different frequencies, element sizes and numbers, and the test platform is used to verify the standard bar. Finally, the bar with natural defects is tested and a detection scheme based on the ultrasonic phased array method is proposed. By the simulation of focusing beam distribution, the distribution of the beam focus in the flat bottom holes can be analyzed, this can help the selection of focusing mode in the detection process and enhance the signal-to-noise ratio of defect detection. The test results show that utilization of the line array transducer to scan the titanium alloy bar can effectively solve the problem of defect detection in the titanium alloy bars.