The study uses the 3D neutronic/thermal-hydraulic coupling transient analysis method to investigate the impact of control rod sequence exchange on key operational parameters in third-generation pressurized water reactors (PWRs). These reactors utilize a control strategy with mechanical compensation of reactivity for load following operation. To ensure this capability, some control rods remain inserted into the core during normal operation. However, to maintain uniformity in fuel burnup distribution, it is necessary to periodically adjust the insertion sequence of control rods. The study analyzes how the process of exchanging control rod sequences affects critical parameters and examines the effects of different control rods exchange speeds and different initial rod positions on parameter perturbation magnitudes. Based on these findings, the research provides valuable reference and insights for nuclear power plant operations.