The present invention discloses an accurate radiation treatment planning system, which mainly comprises a three-dimensional medical image reconstruction module for reconstruction of human organs and the tumor target area, a three-dimensional dose calculation module of high accuracy photon beam, a three-dimensional dose calculation module of high accuracy electron beam, a conventional radiation plan designing module of the photon beam and the electron beam, a conformal radiation designing module of the photon beam and the electron beam, a reverse plan scheme designing module focused on the photon beam treatment. The present invention independently resolves the main and key technology of the radiation treatment planning system. The present invention develops a highly accurate algorithm and a fast precise optimal method of the three-dimensional dose distribution in photon beam and the electron beam, which distributes in non-uniform human medium. The present invention greatly improves accuracy of the embarking dose in tumor target area in patient body. Because the dose calculation speed has been improved dramatically, the advanced conformal radiation treatment planning system and the treatment planning system focused on radiation are feasible for clinical application. The present invention brings important benefits for improving the radiation treatment effect and improving life quality of the patient.