The invention relates to a fine processing method of ramee fiber. The method comprises a step of steaming and boiling ramee tough peel for impurity removal, a steam flash explosion activation treatment step, a cake making cage charging step, a directional catalytic oxidation step, a chemical degumming step and a post treatment step; after the steam flash explosion activation treatment, ferrite solution and activating agents are used for performing directional catalytic oxidation treatment on lignin, pectin and hemicellulose; the steam flash explosion degumming treatment is organically combined with the series technical measures of directional catalytic oxidation and the like, so that the fine processing method of ramee fiber has the characteristics that the degumming effect is good; the obtained ramee fiber finished product has good indexes (such as fineness, length, intensity and the like), high quality, good spinnability and the like; in addition, in the processing process, the chemical consumption is low; the environment-friendly pressure is small; the process control is simple; the public work consumption of water, electricity, steam and the like is low; the efficiency is high; the method is suitable for industrial production, and has good market popularization prospects.