A device for assembling an airbag cover according to the present invention includes: a mounting plate; and an airbag cover which covers the mounting plate, in which a hook portion is formed on the airbag cover, a fastening unit into which the hook portion is inserted, and an insertion member, which pushes the hook portion toward the fastening unit after the hook portion is inserted into the fastening unit, are formed on the mounting plate, and as a result, the airbag cover may be securely assembled to the mounting plate.