Due to the double heterogeneity of the dispersed-particle system, the traditional Volume Homogenization Method (VHM) may have a large calculation deviation. The traditional Reactivity-Equivalent Physical Transformation (RPT) method can be used to deal with the Double-Heterogeneous (DH) system of dispersed fuel particles with relatively small absorption cross section. The deviation is still large for the DH system with dispersed burnable poison particles which has large absorption cross section. The Ring RPT (RRPT) method is an improved RPT method that we have proposed not only to handle the DH system of dispersed fuel particles but also the DH system of dispersed burnable poison particles, and it has been verified in cylindrical DH systems. In this paper the RRPT method is applied to spherical DH systems, and its application range is further analyzed. It is found that the RRPT method has corresponding applicable range when dealing with cylindrical and spherical DH systems. A simple method has been proposed to determine whether a DH system can be processed by the RRPT method, and it provides guidance for the specific application of the RRPT method. And it’s also proved that the RRPT method can treat equivalently the DH systems with the particle types and particle sizes commonly used in engineering. At the same time, through theoretical analysis and calculation verification, and comparison with the calculation results of the Monte Carlo particle model, it is found that the RRPT method is particularly suitable for processing cylindrical DH systems with dispersed-particle burnable poison that the traditional RPT method can’t treat and it is also suitable for spherical DH systems.