Expansion pedestal for metal roof gutter edge and mounting method of expansion pedestal

The invention discloses an expansion pedestal for a metal roof gutter edge and a mounting method of the expansion pedestal. The expansion pedestal comprises a gutter node, wherein the gutter node comprises a gutter, sliding pieces, a water dripping piece, a water sealing adhesive layer, a bolt fixing structure, a roof board plug, a roof system, a wall system and a self-tapping screw, wherein the water dripping piece and the gutter are fixedly connected through the bolt fixing structure; the sliding pieces are fixedly connected with the gutter; and the water dripping piece is tightly connectedwith a roof board through the self-tapping screw. Long round holes are formed in the sliding pieces, the water dripping piece and the gutter are connected through the bolt fixing structure, proper length L of the long round holes is set according to length of the roof, the roof is ensured to slide in a reasonable range, the sliding pieces are directly connected with the gutter, and spacing betweenthe sliding pieces is set