A method for preparing a densely-arranged solar cell string, comprising the following steps: preparing a solar cell, wherein main grids and fine grids of the solar cell are perpendicular to each other; the main grids are segmented electrodes, and welding points for electrical connection between cells are arranged at ends of the segmented main grids; wherein the fine grids, the main grids and the main grid welding points are provided on front and back surfaces of the solar cell; the positions of the main grid welding points on the back surface and the positions of the main grid welding points on the front surface are symmetrical about a center; and, a cell cutting region is further provided on the solar cell, and the cell cutting region is perpendicular to the main grids; printing a strip-shaped hot melt adhesive: printing the strip-shaped hot melt adhesive at the region corresponding to the welding points of the segmented main grids in a direction perpendicular to the main grids, and exposing the welding points; cutting the cell: cutting, along the cell cutting region, the solar cell into a plurality of small cells; coating a conductive adhesive or solder paste: coating the conductive adhesive or solder paste at the main grid welding points on the front surfaces of the small cells; adhering the small cells: superposing main grid welding points on a back surface of one small cell onto main grid welding points on a front surface of another small cell, and heating so that the two small cells are electrically connected through the conductive adhesive or solder paste; and, melting the hot melt adhesive while heating, and solidifying the hot melt adhesive after cooling, so that the two small cells are closely adhered together and the welding points on the two small cells form firm ohmic contact; and repeating the step for the plurality of small cells so that the plurality of small cells are successively connected to form a solar cell string. preparing a solar cell, wherein main grids and fine grids of the solar cell are perpendicular to each other; the main grids are segmented electrodes, and welding points for electrical connection between cells are arranged at ends of the segmented main grids; wherein the fine grids, the main grids and the main grid welding points are provided on front and back surfaces of the solar cell; the positions of the main grid welding points on the back surface and the positions of the main grid welding points on the front surface are symmetrical about a center; and, a cell cutting region is further provided on the solar cell, and the cell cutting region is perpendicular to the main grids; printing a strip-shaped hot melt adhesive: printing the strip-shaped hot melt adhesive at the region corresponding to the welding points of the segmented main grids in a direction perpendicular to the main grids, and exposing the welding points; cutting the cell: cutting, along the cell cutting region, the solar cell into a plurality of small cells; coating a conductive adhesive or solder paste: coating the conductive adhesive or solder paste at the main grid welding points on the front surfaces of the small cells; adhering the small cells: superposing main grid welding points on a back surface of one small cell onto main grid welding points on a front surface of another small cell, and heating so that the two small cells are electrically connected through the conductive adhesive or solder paste; and, melting the hot melt adhesive while heating, and solidifying the hot melt adhesive after cooling, so that the two small cells are closely adhered together and the welding points on the two small cells form firm ohmic contact; and repeating the step for the plurality of small cells so that the plurality of small cells are successively connected to form a solar cell string.