The invention discloses a method for preparing natural-
cellulose based magnetic
porous carbon. The method comprises the steps: firstly, soaking natural
cellulose into a strongly-alkaline solution, carrying out activation for 0.5 to 24 hours, then, carrying out
water washing until the activated
cellulose is neutral, carrying out filtering, carrying out
drying, then, putting the activated cellulose into a
metal salt solution with a catalytic action, carrying out stirring for 0.5 to 24 hours, carrying out filtering, and carrying out
drying, so as to obtain a cellulose /
metal salt mixture precursor; and calcining the obtained cellulose /
metal salt mixture precursor for 0.5 to 12 hours at the temperature of 400 DEG C to 1,000 DEG C in a
reducing atmosphere, naturally cooling the
calcination product to
room temperature, thereby obtaining the natural-cellulose based magnetic
porous carbon. According to the method, the raw materials are cheap and readily available, the equipment and procedures are simple and are easy in operation, and the method is
pollution-free, is low in cost and facilitates industrialized and large-scale production; and the prepared
composite material has properties of both magnetic nano-metal materials and
porous carbon materials, so that the requirements of wave absorbing materials on electromagnetic wave dissipation capability and
impedance matching are excellently met, and the
electromagnetic wave absorption property is excellent.