The influence of polarization behavior and phase transition phenomena on the fracture strength of ferroelectric ceramic materials under high-temperature service conditions remains theoretically underexplored. Existing studies have primarily focused on the individual effects of temperature or electric field on fracture strength, while temperature-dependent theoretical models that quantitatively characterize coupled effects based on fundamental physical mechanisms are still lacking. In this work, a novel temperature-dependent theoretical model for the quantitative characterization of fracture strength in ferroelectric ceramics is developed, incorporating the effects of polarization and phase transitions. The model is constructed based on Li's energy equivalence principle by integrating the contributions of thermal energy, strain energy and polarization energy to the critical energy threshold for fracture, and by establishing equivalence relations among these energy terms. This model explicitly relates fracture strength to fundamental material parameters, including temperature, Young’s modulus, dielectric constant, electric field strength, and melting point, without relying on any fitting parameters. Validation using high-temperature fracture strength data for GaN piezoelectric semiconducting ceramics, as well as PZT-4 and PZT-5H ferroelectric ceramics, demonstrates good agreement between the model predictions and experimental results. This study provides theoretical tools and potential non-destructive testing methods for the quantitative analysis of the effects of temperature and electric field on material fracture behavior.