With the aging of the unit, the core fuel cooling performance of QINSHAN CANDU reactor decreases. To ensure the safe operation of the reactor, it needs to do regular analysis of ROP TSP. The analysis result is applied by correcting the CPPF which is used to calibrate ROP detectors to continuously track thermal hydraulic, pressure tube creep and other parameters. This paper focuses on the analysis of the ROP related parameters correction method for CPPF. Based on the actual operation data of unit 1, it analyzes the comparison of relevant parameters before and after correction, as well as the influence of operation such as refueling. Finally, it summarizes the operational optimization and countermeasure that can be taken.