In order to understand the electrical characteristics of all kinds of reservoirs under different temperature, the relationship between temperature and the resistivity of homogeneous core saturated with formation water is selected as the starting point of the research, and based on the effective medium theory HB equation, the semi-empirical resistivity model of the core is established. The temperature parameter is introduced in the resistivity model for the first time by considering the effect of temperature on the resistivity of formation water and the resistivity of the rock particles respectively. And the applicability of this model is verified by the experimental data in the relevant literature which can effectively reflect the relationship between temperature and the resistivity of homogeneous core saturated formation water. The establishment of this model has certain theoretical basis, which will help further study the change rules of core resistivity in reservoir environment.