The resistivity characteristics of 2D SiC/SiC composites were studied experimentally. In the oxygen-free environment, the resistivity increases when temperature decreases. With curve fitting, the mapping relationship between resistivity and temperature is established. After oxidation at 1300 ℃ in the air for 20 and 60 h, the conductivity of composites is greatly reduced due to the oxidation of the PyC interface and the SiC matrix. The degree of oxidation was characterized by the content of SiO₂, and the quantitative relationship between resistivity and oxidative damage was obtained. The changes in resistivity and stress with strain are similar. In the linear segment of stress-strain curve, with few matrix cracks the stiffness is almost unchanged, and the resistivity increases slowly. In the non-linear section, the resistivity rate and stiffness increase quickly because crack increases rapidly. They eventually stabilize when the increase in cracks slows down.