Abstract: This paper presented an ultrasonic phased array plane wave imaging (PWI) algorithm. Firstly, the data acquisition method for plane wave imaging technology was described. The time-of-flight calculation formulas were then derived for scenarios without and with wedge blocks, followed by an explanation of the principles and steps of plane wave imaging. Additionally, the paper described the time-of-flight calculation methods for different modes of the algorithm and the handling of the algorithm's effective region. Experimental results of plane wave imaging were presented. A comparison was made between plane wave imaging and phased array imaging, as well as full matrix capture-based full focusing imaging detection results, to summarize the advantages and limitations of the plane wave imaging algorithm. Finally, the paper analyzed the application of plane wave imaging algorithm in light of its advantages. The experimental results showed that the PWI-TFM (plane wave imaging-total focusing method) imaging algorithm had multiple advantages compared to existing imaging algorithms and was a highly practical imaging algorithm.