The study investigated algorithms for processing the gamma spectrum of PVT detectors. Various commonly used algorithms and algorithms were examined for handling the gamma spectrum of PVT detectors. During the research, the Energy Weighted Counts (EWC) algorithm was selected and implemented to process the gamma spectrum using simulated data of gamma scattering spectra on PVT detectors. Specifically, the energy-weighted algorithm was applied to effectively differentiate between the gamma spectra of three important isotopes Cs137, Co60, and I131. The results of the study demonstrated the success in meeting the specified requirements, especially in selecting the optimal algorithm for identifying the three isotopes on the PVT detector, all achieved through the utilization of the GEANT4 simulation software. This research not only provided a detailed insight into gamma spectrum processing but also proposed an effective algorithm using simulation software to explore and evaluate algorithms on PVT detectors. This marked a significant step in the research and development within this field.