PTFE composites filled with SiO2 and TiO2 were prepared through wet process and sintered by Muffle furnace and Hot pressing. The density, microstructure, dielectric properties and thermal expansion of the composite materials doped with different ratios of these two ceramics and sintered by different methods were systematically investigated. The experimental results show that the composites prepared by hot pressing process exhibit better stability in density, low water absorption and relatively higher dielectric loss compared with the samples sintered by Muffle furnace.The ROM and Kerner models can be used to predict the coefficient of thermal expansion of composites, and the theoretical values predicted by these two models match well with the experimental values. The dielectric constants of the composites calculated by Lichtenecker module also match well with the experimental values for both sintering methods.