[en] In this paper, the low-field dielectric behaviors of 0.7PbFe_2/3W_1/3O₃-0.3PbTiO₃ (0.7PFW-0.3PT) relaxor ferroelectrics sintered at various temperatures have been investigated. The X-ray diffraction detector, the diffusion phase transition model and the spin glass model are used to analyze the dielectric characteristics. According to our experimental results and the theoretical analysis, it is found that the structure is changed from cubic to tetragonal and the diffusion phase transition characteristics and the spin glass behavior is weakened as the sintering temperature increases. In conclusion, the normal ferroelectric characteristics are more obvious as the sintering temperature increases in this system