The invention belongs to the field of electric power supply and discloses a single-phase power transformer. The single-phase power transformer comprises a magnetic core, a coil and a shell. The invention further discloses a transformer case. The transformer case is prepared by 18 parts of silicon carbide, 15 parts of bauxite, 14 parts of quartz sand, 12 parts of magnesium oxide, 3 parts of lead sulfate, 2 parts of lithium-based bentonite, 2 parts of borax, 1 part of dried calcium sulfate and 1 part of palygorskite. The prepared transformer case can effectively prevent electromagnetic radiation and is good in corrosion-resistant effect and superior to like products on the market.