The invention discloses a segmenting and trimming device for an aeronautical facility plate and a work method of the segmenting and trimming device for the aeronautical facility plate. The segmentingand trimming device for the aeronautical facility plate comprises a console, a front bearing frame, supporting and feeding frames, holding platforms, a cutting and trimming platform and a back feedingframe. The front bearing frame is arranged at one end of the upper side of the console in an inclined manner. The supporting and feeding frames are longitudinally arranged at the two ends of the upper end face of the console. The two ends of the console are both longitudinally provided with the holding platforms. The cutting and trimming platform is longitudinally arranged above the edge of one side of the console. The segmenting and trimming device for the aeronautical facility plate has the beneficial effects that after cutting discs cut and segment plates, third hydraulic pumps on moving seats drive fifth motors to extend front and back, and polishing sheets are aligned with the cut faces of the plates to conduct polishing; besides, during polishing, each sliding connection block at the bottom of the corresponding moving seat drives a rotating gear through a fourth motor to roll in cooperation with a plurality of rolling teeth in a rolling hopper, so that each moving seat and eachpolishing ring are driven to move front and back to conduct polishing; and in this way, it is guaranteed that the segmenting and trimming device for the aeronautical facility plate more completely andmore thoroughly polish the plate segments, and meanwhile the segmenting and trimming device for the aeronautical facility plate can more efficiently polish and trim the plate segments.