Abstract: To verify the accuracy of calculating the ultimate shaft resistance and ultimate tip resistance of PHC piles based on cone penetration test (CPT) parameters, this paper employs multiple testing methods for comprehensive investigation. While the overall effectiveness of CPT in predicting the ultimate bearing capacity of PHC piles has been validated by numerous scholars, research specifically examining the prediction accuracy of ultimate shaft resistance and tip resistance has been lacking and requires validation with actual test data. This study combined pile load test (PLT) with kentledge, distributed fiber optic sensing (DFOS) technology, and Osterberg cell (O-cell) test. The PLT provided actual data on ultimate shaft and tip resistance. DFOS technology enabled real-time monitoring of shaft resistance distribution along the pile. The O-cell test precisely measured the pile tip resistance. The ultimate shaft resistance and tip resistance calculated from CPT parameters were then compared and analyzed against the results obtained from these tests. Key findings include: Compared to using CPT sleeve friction, predictions of the ultimate shaft resistance of PHC piles in various soil layers based on cone tip resistance demonstrate superior accuracy and stability; For calculating the equivalent cone tip resistance at the pile tip, considering a depth range of 1.0d to 1.5d below the pile tip (where d is the pile diameter), and applying a tip resistance correction factor of 0.40 to 0.50 for dense sandy soils, yields results more consistent with actual conditions. This research demonstrates that using CPT parameters to calculate both the ultimate shaft resistance and ultimate tip resistance of PHC piles yields high accuracy. The ultimate shaft resistance should be determined by cone tip resistance. For ultimate tip resistance calculations, the tip resistance correction factor should be rationally selected considering pile diameter, pile tip embedment depth, and load characteristics. The study provides a scientific basis for the design of PHC piles.