Preparation method of bastose

The invention discloses a preparation method of bastose. The preparation method is characterized by comprising the following steps of fiber pretreatment; alkali treatment; acid treatment; ultrasonic-assisted bio-enzyme treatment; washing; drying; and bastose obtaining. The preparation method is short in process flows, few in drying steps as well as low in time and energy consumption; and the used additives are environment-friendly additives and are low in dosage. By using the preparation method disclosed by the invention, the lignin and hemicellulose removal effect is good, the content of alpha-cellulose in the prepared bastose is high, the polymerization degree of the bastose is easily controlled, and the structure and performance of the bastose are not remarkably influenced.