The western margin of the South China Sea is characterized by a strike-slip fault system,and it is one of the most complex structures and relatively lack of research at present of the various continental margins in the South China Sea. In this paper thermal simulations of the mid-south section of the western margin strike-slip fault zone were conducted because that the slip zone has significant implications for the formation and evolution of the surrounding petroliferous basins. The simulation software Comsol is used to calculate the temperature and heat flow generated by strike-slip friction in the middle-south section of the western marginal strike-slip fault zone at a time scale of about 30Ma. The results show that the maximum temperature generated by the strike-slip friction in the Yuedong-Wanan fault is about 434℃ and the maximum heat flow generated is about 55mW/m² at the 30Ma and the depth of 70km while the maximum temperature generated in the Lupaer fault is about 300℃ and the maximum heat flow generated is about 40mW/m² at the same time and the same depth. Compared with the measured results,the error is controlled within 15%. Our results provide a basic understanding of the thermal history and maturation history of source rocks in the Cenozoic Basins around the western marginal slip zone,and have important theoretical significance and practical application for the evaluation of the potential hydrocarbon exploration in the strike-slip fault zone.