The invention discloses a processing method of a down-proof shell fabric of a super-flexible noiseless down quilt and relates to the technical field of down quilt processing. The processing method mainly comprises the following steps: (1) blended yarn processing; (2) blended yarn dyeing; (3) shell fabric weaving; (4) shell fabric calendering pre-processing; and (5) shell fabric calendering. By taking modal fibers and polyterephthalic acid 1,3-propylene glycol ester fibers as raw materials, the prepared shell fabric fully combines excellent characteristics of two fibers, in particular flexibility; in the blended yarn dyeing process, a flexible aid is added, so that the processed shell fabric is endowed with excellent flexibility at the same time through the dyeing step; by performing calendering pre-processing on the shell fabric, the flexibility, air and water vapor permeability and downproofness of the shell fabric are enhanced under the action of a calendering aid.