Abstract: Advanced imaging algorithms promote the development of ultrasonic phased array technology. Total focusing method (TFM) is a virtual focusing post processing and defect image reconstruction algorithm based on full matrix capture. In this paper, based on the full matrix data mode of one-dimensional linear phased array longitudinal wave probe, the algorithm is programmed by using Matlab software combined with the open source function package of Field Ⅱ. The imaging effects of TFM and 1/2 matrix method are compared, and the influencing factors of defect resolution are analyzed. Finally, the algorithm is verified experimentally with the standard test block. The simulation results show that both TFM and 1/2 matrix method can be used for defect reconstruction without significant difference in effect, and the width and frequency of the excitation pulse have great influence on the image resolution. Experimental results show that the imaging method of 1/2 matrix can effectively reduce the amount of calculated data, but it also loses part of the defect information at the edge of the detection area, and its imaging effect is slightly worse than that of TFM.