The invention relates to the technical field of textile fabrics, in particular to an anti-static flame-retardant anti-oil washing cotton and linen blended fabric, a preparation method thereof and application of the blended fabric. The method includes the steps: (1) preparing a primary blended fabric; (2) impregnating the primary blended fabric into protease impregnation liquid to obtain a first impregnated fabric; (3) impregnating the first impregnated fabric into nano-particle impregnation liquid to obtain a second impregnated fabric; (4) treating the second impregnated fabric by flame-retardant finishing liquor, and drying the treated second impregnated fabric to obtain the anti-static flame-retardant anti-oil washing cotton and linen blended fabric. Linen fibers, cotton fibers and protein fibers are slivered, spun and woven to form the primary blended fabric. The fabric is soft in hand feeling, comfortable, multifunctional and widely applied to the fields of garments and home textiles and has anti-static, flame-retardant and anti-oil performances.