The invention belongs to the technical field of a sealing-up and plugging materials, and particularly relates to a method for preparing plugging agents. The method includes smashing diatomaceous earth,
bentonite,
sepiolite and the like and mixing and stirring the diatomaceous earth, the
bentonite, the
sepiolite and water to obtain suspension; collecting
emulsion from rubber trees, mixing and heating the
emulsion, heavy
calcium carbonate, carboxymethyl celluloses and
polyamide fibers to obtain first mixtures; adding
silane coupling agents into the first mixtures and carrying out ultrasonic treatment to obtain modified natural
emulsion; mixing, heating and stirring the modified natural emulsion and lauroyl
diethanolamine solution to obtain second mixtures, adding initiators, the suspension and cross-linking agents into the second mixtures, stirring the second mixtures, the initiators, the suspension and the cross-linking agents to obtain third mixtures and adding
acrylamide solution into the third mixtures; carrying out reaction and then discharging and
drying reaction products to obtain the plugging agents. The method has the advantages that the plugging agents prepared by the aid of the method are high in blocking speed and plugging success rate, formed plugging
layers are high in loading capacity, good plug forming effects can be realized, repeated leakage can be prevented, and the plugging agents are little in environmental influence and free of
pollution, are non-toxic and can be constructed safely and quickly.