The invention provides a high-end pajamas fabric and a preparation method thereof. Cotton fibers and banana stalk fiber refined dry flax are firstly woven into core spun yarns, and then the core spun yarns are blended with silk fibers; the blended fibers not only have the skin care characteristic of the silk fibers, but also is further reinforced in moisture adsorption and air permeability; the banana stalk fiber refined dry flax used in the invention recycles waste banana stalks and accords with the requirements of the national circular economy, and cost of the high-end fabric is reduced; in a dyeing process, a small quantity of silkworm pupa protein is added, so that fragrance of a pajamas can be reinforced, and sleeping quality can be promoted; according to the high-end pajamas fabric and the preparation method thereof, which are provided by the invention, the banana stalk fiber refined dry flax is used as a core and is coated with natural high-quality cotton yarns, and the banana stalk fiber refined dry flax and the natural high-quality cotton yarns are woven into the core spun yarns, so that not only is the defect of the rough surface of the banana stalk fiber refined dry flax overcome, but also moisture adsorption and air permeability of the blended fabric is promoted; the preparation method is a novel natural fiber optimization utilization process.