Abstract: We analyzed the material resistivity. Carbon fiber volume fraction is the main factor influencing the material resistivity. According to the measured data of material surface, carbon fiber volume fraction of material can be estimated. According to the measured data of multiple specimens, the relationship curve between carbon fiber volume fraction and resistivity of material can be fitted. So according to the estimated data of the carbon fiber volume fraction, the resistivity of the material can be estimated. According to the braiding angle and pitch length of 3D braided carbon fiber composites, the resistivity of material can be estimated, which can be used for material analysis of eddy current nondestructive testing.