The invention discloses a preparation method of a fast-dissolving gefitinib tablet pharmaceutical composition and belongs to the technical field of pharmaceutical preparations. The fast-dissolving gefitinib tablet pharmaceutical composition prepared by adopting the preparation method of the fast-dissolving gefitinib tablet pharmaceutical composition contains a gefitinib core and a film coating, wherein the film coating wraps the outer end of the gefitinib core, the outer surface of the gefitinib core is provided with a plurality of uniformly distributed hemispherical accommodating holes, expansion balls are inlaid and fixed in the hemispherical accommodating holes, the outer surfaces of the expansion ball are fixedly connected with a plurality of expanded and crack-guiding fibers, it can be achieved that an edible expansion agent is added in the gefitinib tablet, a large amount of gas is generated after acid-base chemical reaction in the presence of water, the fibers rapidly expand themselves and disintegrate to make the gefitinib tablet crack, the gefitinib tablet cooperates with a traditional disintegrating agent to make the gefitinib tablet rapidly crack into fine and small granular powder, the dissolution of gefitinib is promoted, accordingly the functional ingredients are rapidly absorbed by a patient, and a therapeutic effect is played.