The invention relates to the technical field of photonic devices, in particular to a vertical coupling grating coupler bonded by metal and a manufacturing method thereof. The grating coupler comprises a carrier piece, a metal bonding layer serving as a reflective mirror layer, a lower limiting layer of slab waveguide, tapered waveguide and submicron waveguide, a sandwich layer of the slab waveguide, the tapered waveguide and the submicron waveguide , an upper limiting layer of the slab waveguide, the tapered waveguide and the submicron waveguide and an optical fiber, wherein the carrier piece is formed by a silicon wafer or a glass sheet, the lower limiting layer is formed by a DVS-BCB layer, the sandwich layer is formed by a silicon layer, the upper limiting layer is formed by a silicon oxide oxidation layer, the slab waveguide, the tapered waveguide and the submicron waveguide are mutually linked up in the horizontal direction, a coupling grating and a reflecting grating are manufactured on the surface of the slab waveguide sandwich layer, and one end of the optical fiber is vertically close to the surface of the upper limiting layer of an SOI with a silicon substrate removed. According to the vertical coupling grating coupler, high-efficiency vertical coupling between the optical fiber and planar optical waveguide can be realized.