To address the shortcomings of traditional radiation protection training in nuclear power plants (NPPs), which fails to provide accurate quantitative assessment results in preventing the spread of radioactive contamination and reducing radiation doses, a training system has been developed based on three-dimensional dose field and virtual reality (VR) technologies. Targeting typical high-radiation-risk operational scenarios in NPPs, the system evaluates radioactive source terms and individual effective doses within plant buildings, visually presents the dose contributions of radiation sources in the operating environment to trainees, effectively enhances the efficacy of radiation protection training, and contributes significantly to reducing collective doses in NPPs.