2.5-dimension continuous silicon carbide fiber reinforced silicon dioxide composites (SiCf/SiO2) was fabricated by vaccum infiltration. The effects of different interfaces on SiC fabric preform on the mechanical properties of the composites were studied. The bending strength of the composites， in which the fabric without interface，was 52.2MPa, while coating the fabric with pyrolytic carbon (PyC) and PyC/SiC multi-layer interfaces enhanced the bending strength to 67.4 and 180.3MPa. However, the interfaces also declined the toughness of SiCf/SiO2 composites. The surface morphology of fractured composites was analyzed by Scanning electron microscope. The results show that the interfaces not only increase the bending strength but also enhance the bonding between the matrix and fibers which improves the load transfer from the matrix to the fibers. The PyC/SiC interfaces protect the SiC fibers against being damaged by the water released during the processing of sintering and promote the mechanical properties of SiCf/SiO2 composite.