▎ 摘　　要

NOVELTY - Method for preparing plant fiber-based microwave absorber, involves (a) using plant fiber as raw material, and placing in a heating chamber of a heating device, (b) passing an inert gas to the heating chamber as a protective gas, increasing the temperature to 400-1200℃, and carbonizing the plant fibers, and treating at this temperature for ≯5 hours to obtain carbonized fibers, and (c) cooling the heating chamber to room temperature, taking out the carbonized plant fiber, pulverizing as required to obtain a carbonized fiber material, and compounding with a polymer matrix at a mass filling rate ≯20 wt.% to obtain the microwave absorber. USE - The method is useful for preparing plant fiber-based microwave absorber used in the field of electromagnetic wave absorption (claimed). ADVANTAGE - The prepared carbonized fiber effectively absorbs electromagnetic waves, and the absorption frequency band can cover the radar band by adjusting the heat treatment temperature of the paper fiber, and the X and Ku bands and most of the K and Ka bands are simple and easy to obtain, economical, and suitable for mass production.