The invention discloses a making method for pre-baked mashed potato bread. The method comprises the steps that 1, 170 g of high gluten flour, 132 g of mashed potato, 32 g of water, 40 g of sugar, 8 g of milk powder, 0.8 g of bread improver, 20 g of butter, 2 g of salt, 16 g of eggs and 4 g of yeast are accurately weighed; 2, dough kneading, standing, shaping and fermentation are conducted; 3, pre-baking is conducted for 8 min with the bottom fire being 180 DEG C and the surface fire being 230 DEG C, and then cooling is conducted to reach the room temperature under the environment with the humidity being 75%; 4, dough is wrapped by preservative film and moved to the place at -18 DEG C for frozen storage; 5, the dough returns to the room temperature and is brushed with egg liquid and baked to be golden yellow with the bottom fire being 180 DEG C and the surface fire being 230 DEG C. The method has the advantages that the bread is made into a semi finished product for frozen storage, when a person want to eat the bread, he / she only needs to bake the bread, the obtained bread has the burnt flavor and the unique flavor of potatoes, the bread is soft and elastic and has the color of thick and uniform golden brown, the surface is a smooth curved surface and is free of crease and not likely to fall off, the bread core is soft, wet, milky white, glossy, fine and uniform in pore, soft, palatable, non-sticky and pure in taste, and the quality is almost the same as that of bread made from fresh dough.