Abstract: Objectives: Phase Center Variations (PCV) of GNSS receivers are a critical factor affecting the accuracy of BDS real-time precise point positioning (RT-PPP) and tropospheric parameter estimation. However, systematic evaluations of receiver PCV in RT-PPP remain insufficient in existing studies. This research aims to quantitatively assess the impact of millimeter-level receiver PCV errors on RT-PPP positioning and tropospheric parameter estimation, and to evaluate the performance of different PCV correction models for zenith tropospheric delay (ZTD) and precipitable water vapor (PWV) retrieval. Methods: Using BDS and GPS satellite observations, comparative experiments are conducted with and without receiver PCV corrections. The effects of millimeter-level PCV errors on RT-PPP positioning and tropospheric parameter estimation are systematically evaluated. Furthermore, observations from five different types of GNSS receiver antennas co-located at self-established stations are collected. Taking co-located radiosonde water vapor data as reference, three two-dimensional full-directional and two one-dimensional elevation-dependent PCV correction models are systematically investigated for their impacts on ZTD and PWV retrieval accuracy. Results: Under BDS positioning mode, after applying receiver PCV corrections at IGS stations, the positioning accuracy improvements in the North, East, and Up directions are 1.86%, 1.97%, and 3.50%, respectively. A stable 2:1 proportional relationship is observed between the receiver PCV error and the improvement in ZTD estimation accuracy. For the three two-dimensional full-directional PCV models, the retrieved ZTD accuracies are 8.93 mm, 10.19 mm, and 12.93 mm, and the PWV accuracies are 2.54 mm, 2.65 mm, and 2.67 mm, respectively. For the two one-dimensional elevation-dependent PCV models, the retrieved ZTD accuracies are 15.14 mm and 16.25 mm, and the PWV accuracies are 3.11 mm and 3.70 mm, respectively. The data completeness rates for the five antenna types are 96.00%, 94.79%, 94.60%, 94.57%, and 94.12%. Conclusions: Receiver PCV corrections effectively improve BDS RT-PPP positioning accuracy and the estimation of tropospheric parameters. Among the three two-dimensional full-directional PCV models and two one-dimensional elevation-dependent PCV models, the two-dimensional models demonstrate superior performance in ZTD and PWV retrieval. This study quantifies the impact of receiver PCV corrections on BDS RT-PPP positioning and tropospheric parameter estimation, providing a theoretical basis for the selection of receiver antenna types for different application scenarios.