The macro effective thermal conductivity of satin weave thermoset prepregs evolves dynamically in the preforming and demonstrates itself as in function of yarn angle and temperature. Accurate knowledge of it is fundamental for the high-fidelity heat transfer and deformation analysis in the preforming simulation. In this paper, a method combing virtual deformation modeling and multiscale thermal homogenization was proposed to analyze the macro effective thermal conductivity evolution of satin weave thermoset prepregs during preforming. The virtual deformation modeling based on the transverse Neo-Hookean hyper-elastic material law was used to acquire yarn geometry in the meso thermal homogenization analysis. Predicted yarn shapes were validated with the X-ray μCT images. The macro effective thermal conductivities at different temperatures and yarn angles were computed with the Macro/Meso thermal homogenization. It shows that the in-plane macro effective thermal conductivities evolve nonlinearly and greatly with respect to both temperature and yarn angle variation, while the transverse macro effective thermal conductivities evolve almost only with temperature variation. The predicted thermal conductivities were compared with specifically designed thermal experiments. Good agreement is noted, demonstrating the effectiveness of the proposed method. This work provides a new alternative way for predicting thermal conductivities of woven thermoset prepregs.