Abstract: Advancements in science and technology, coupled with increasingly stringent national standards for bar quality, demand higher imaging quality and efficiency in ultrasonic testing. To address this need, this study integrates a phase coherence imaging (PCI) algorithm with ultrasonic phased array sector scanning for the inspection of a 90-mm diameter bar containing four flat-bottom holes of varying depths. Experimental results demonstrate that compared to the traditional total focusing method, sector scanning provides higher amplitude and equivalent array performance index levels, while significantly reducing imaging time. However, both techniques are susceptible to secondary wave and clutter interference from the water coupling layer. Application of the PCI algorithm substantially reduces structural noise of the fan-shaped scanning image, markedly improving defect identification. Among them, the S-SCF algorithm demonstrated the best overall performance, achieving a maximum signal-to-noise ratio improvement of approximately 5 dB and effectively suppressing secondary waves and clutter interference in the water layer. Integrating the S-SCF algorithm into phased array inspection instruments shows strong potential for enhancing practical engineering applications.