In response to the problem for non-washable and poor taking comfortable characterizations of smart electronic fabrics at present, two different organizational structures of fabric sensors with plain weave and double weave are designed. The basic principle of design of fabric sensor is: the core-spun yarn made of metal wire is used as core wire, the structural unit with capacitor function is built by interweaving warp with weft, and the induction of fabric to external pressure is reflected by testing changes in capacitance of fabric. The models of equivalent electronic circuits of two fabric sensors with plain weave and double weave are analyzed, and the relationships between area and capacitance characteristics of fabric sensor are discussed. The results show that: the larger the fabric area, the greater the capacitance, and the capacitance of 36cm2 fabric is maximum with 100Hz test frequency; under the condition of the same area and test frequency, the capacitance of plain weave fabric is greater than that of double-layer fabric under no pressure, but the increasing rate of capacitance of double-layer fabric is larger than that of plain weave fabric under the same pressure.