at a curing temperature of 40 u00b0 c and then mechanical teasing and extension refining were performed to prepare the pineapple leaf fiber ramie stripes the compound swelling additive solution of the pineapple leaf fiber is compounded of a swelling protein agent cellulase hemicellulase pectinase and non ionic penetrating agent with a dosage of 0 5 of the weight of the pineapple leaf fiber and a bath ratio of 1 10 wherein the dosage of the swelling protein agent in the compound swelling additive solution of the pineapple leaf fiber is 0 5 of the weight of the pineapple leaf fiber the dosage of the cellulase is 0 3 of the weight of the pineapple leaf fiber the dosage of the hemicellulase is 0 5 of the weight of the pineapple leaf fiber the dosage of the pectinase is 0 5 of the weight of the pineapple leaf fiber and the dosage of the penetrating agent is 0 5 of the weight of the pineapple leaf fiber 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 1 0 sulfuric acid solution with a temperature of 80 u00b0 c a bath ratio of 1 20 an ultrasonic frequency of 40 khz and a time of 120 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.