The invention provides a preparation method of a double-faced generating type double-glass photovoltaic module, belonging to the technical field of solar cells. The preparation method comprises the following steps: putting a group of battery pieces into a battery piece carrying box, wherein the front surfaces of the battery pieces face upwards; straightening a plurality of solder strips, cutting the solder strips to obtain the solder strips with the length sizes corresponding to the battery pieces, and sequentially putting the solder strips to preheating positions of a conveying belt of a welding platform in parallel, wherein a concave-convex structure is arranged on the upper surface of the conveying belt; putting the battery pieces in the battery piece carrying box to corresponding positions on the solder strips, and putting the straightened solder strips on the battery pieces, wherein the back surfaces of the battery pieces are in contact with the solder strips, and the front surfaces of the battery pieces face upwards; repeatedly putting the solder strips and the battery pieces until the piece number requirement of the battery pieces is met; conveying the put battery pieces to a soldering unit through the conveying belt, and soldering; and after soldering tin of the solder strips in contact with the conveying belt is melted and solidified, forming a concave-convex structure matched with the concave-convex structure on the surface of the conveying belt, so as to finish the preparation of back surface reflective strips of the battery pieces. By virtue of the preparation method, the photovoltaic conversion efficiency is improved.