The invention discloses an air-cooling cylinder head of a gasoline engine and a gasoline engine. The air-cooling cylinder head of a gasoline engine comprises a cylinder head main body (1), and an intake passage (3), an exhaust passage (2) and a spark plug mounting hole (6) arranged in the cylinder head main body (1), a plurality of cooling fins (4) is arranged on the outer surface of the cylinder head main body (1), a combustion chamber surface (5) is formed on the inner side of the cylinder head main body (1), a longitudinally through air-cooling passage I (8) is arranged on the same side of the cylinder head main body (1) as the intake passage (3) and the exhaust passage (2), a transversally through air-cooling passage II (7) is arranged between the intake passage (3) and the exhaust passage (2), and both the longitudinally through air-cooling passage I (8) and the transversally through air-cooling passage II (7) are kept away from function holes on the cylinder head main body (1). In the technical solution of the invention, cooling air flows through the outer surface of the combustion chamber wall from different directions to sufficiently decrease the temperature of the combustion chamber, so that the cylinder head has excellent cooling efficiency, and the power of the gasoline engine is increased.