A photovoltaic module, comprising: a solar cell string comprising a plurality of solar cells , each of the plurality of solar cells has a thickness within a range of 0.17 mm to 0.19 mm, adjacent two of the plurality of solar cells being connected by a solder strip , wherein the solder strip is connected to a front surface of one solar cell and to a back surface of another solar cell, and a long-side size of the solar cell is within a range of 150mm to 220mm; two protective adhesive layers respectively covering a front surface and a back surface of the solar cell string, wherein a size difference between a thickness of one protective adhesive layer and a thickness of the solder strip is defined as a first thickness, a ratio of the first thickness to the thickness of one protective adhesive layer is not less than 5% and not greater than 15%; a transparent plate covering a surface of the protective adhesive layer on the front surface of the solar cell string; and a back plate covering a surface of the protective adhesive layer on the back surface of the solar cell string; each of the plurality of solar cells comprises a single-layer region and an overlapping region, and adjacent two of the solar cells are stacked in the overlapping region, and the protective adhesive layer has a gram weight of 245g/ m 2 to 430g/ m 2 ; the solder strip comprises a reflective section and a flat section connected to the reflective section, the reflective section is arranged in the single-layer region, and the flat section is at least partially arranged in the overlapping region; and a cross section of the flat section is a cashew-shaped surface, and the cashew-shaped surface is defined by planar regions on both sides of the solder strip in a thickness direction and arc-shaped regions on both sides of the solder strip in a width direction. a solar cell string comprising a plurality of solar cells , each of the plurality of solar cells has a thickness within a range of 0.17 mm to 0.19 mm, adjacent two of the plurality of solar cells being connected by a solder strip , wherein the solder strip is connected to a front surface of one solar cell and to a back surface of another solar cell, and a long-side size of the solar cell is within a range of 150mm to 220mm; two protective adhesive layers respectively covering a front surface and a back surface of the solar cell string, wherein a size difference between a thickness of one protective adhesive layer and a thickness of the solder strip is defined as a first thickness, a ratio of the first thickness to the thickness of one protective adhesive layer is not less than 5% and not greater than 15%; a transparent plate covering a surface of the protective adhesive layer on the front surface of the solar cell string; and a back plate covering a surface of the protective adhesive layer on the back surface of the solar cell string; each of the plurality of solar cells comprises a single-layer region and an overlapping region, and adjacent two of the solar cells are stacked in the overlapping region, and the protective adhesive layer has a gram weight of 245g/ m 2 to 430g/ m 2 ; the solder strip comprises a reflective section and a flat section connected to the reflective section, the reflective section is arranged in the single-layer region, and the flat section is at least partially arranged in the overlapping region; and a cross section of the flat section is a cashew-shaped surface, and the cashew-shaped surface is defined by planar regions on both sides of the solder strip in a thickness direction and arc-shaped regions on both sides of the solder strip in a width direction. <EOS>