The invention relates to a fireproof plugging construction method and device for a joint of a partition and a roof and belongs to the field of building construction methods. The fireproof plugging construction method is implemented according to following steps: S00, filling the uneven surface of a profiled steel plate at the joint of the partition and the roof with rock wool; S10, fixedly connecting a pressing plate with the profiled steel plate; S20, fixing a sliding rail on the pressing plate; S30, fixing the top of a keel in the sliding rail; S40, fixedly connecting the partition with the vertical keel, and filling a space between the top of the partition and the pressing plate with a fireproof sealant. By using the fireproof plugging construction method, cavities and gaps between the keel and the profiled steel plate can be avoided effectively, and contact area between the partition and the profiled steel plate is enabled to have maximum sealability, so that fireproof performance of the joint of the partition and the roof is improved greatly and the fireproof grade of a whole partition system is enabled to reach standards.