a swelling additive then subjected to chemical degumming treatment after the swelling treatment to prepare pineapple leaf fiber degummed ramie and finally teased and refined to obtain pineapple leaf fiber ramie stripes a loosening fiber structure makes fibers slip easily under the effect of an external teasing and refining force while the invention may increase the fiber looseness improve the fiber fineness improve the fiber quality enable a chemical degumming additive to enter the inside of the fiber more easily reduce sewage discharge during degumming and decrease the degumming treatment cost application_number US 201614994136 A description the invention will be further described in details hereinafter by examples and these examples are merely for explanation of the invention and are not intended to limit the scope of the invention a pineapple leaf fiber fine treatment method includes the following steps the pineapple leaf fiber was subjected to ultrasonic treatment in a pretreatment solution wherein the pretreatment solution was 0 15 sulfuric acid solution with a temperature of 50 u00b0 c a bath ratio of 1 15 an ultrasonic frequency of 30 khz and a time of 40 min then the pineapple leaf fiber was subjected to washing and dewatering treatment the pineapple leaf fiber after pretreatment was put into a compound swelling additive solution for swelling treatment at a temperature of 55 u00b0 c a ph value of 7 and a reaction time of 40 min the pineapple leaf fiber after swelling treatment was subjected to high temperature degumming treatment then the pineapple leaf fiber was subjected to washing and dewatering and then put into 5 u02dc 15 hydrogen peroxide to bleach for 30 min at a temperature of 70 u00b0 c the bleached pineapple leaf fiber was soaked in a solution containing.