The invention relates to the technical field of clothing fabrics, in particular to a fabric with low washing shrinkage rate and a preparation process thereof. The fabric is formed by weaving of a composite yarn, the composite yarn is formed by laminating a surface yarn, an elastic fiber yarn and a bottom yarn, after lamination shaping, the surface yarn forms a surface layer, the elastic fiber yarnforms an elastic middle layer, and the bottom yarn forms a base layer; the surface yarn is unshrinkable wool fiber with a metric number of 1/80Nm-1/60Nm and a count of 90S; the elastic fiber yarn islow-temperature spandex with Denier of 30-60D; and the base yarn is polypropylene fiber with Denier of 45-75D and a hole count of 45-75F. By adopting the three yarn fibers for blending weaving, the prepared fabric includes three sequentially formed yarn layers, and the middle layer has elasticity, thus improving the wearing comfort and skin friendliness of the fabric, and the fabric has the functions of environmental protection, warmth retention, machine washability, no ironing and the like, does not generate stuffiness and skin-sticky feel, is comfortable to wear, and low in washing shrinkagerate.