The asymmetric wetting Janus fabric with double-woven structure was designed by using two systems of warp yarns and two types of the weft yarns with distinct wettability. The result shows that the fabric with double-woven structure possesses the asymmetric wettability with superhydrophobicity on one side while superhydrophilicity on the other side. This asymmetric wettability realizes a unidirectional permeation and oil/water separation effect. The efficiency of oil/water separation could be simply controlled by varying fabric densities; thus, suitable density should be regarded as an important factor in this system. In water removal mode, the separation efficiency and separation flux reached 99% and 2.5Lm(-2)s(-1), respectively. In de-oiling mode, the separation efficiency and separation flux reached 96% and 8Lm(-2)s(-1), respectively. According to this work, the as-prepared asymmetric wettability Janus fabric with double-woven structure is promisingly applied to oil/water separation and other related applications.