According to a certain vehicle parameters and actual working conditions, a coaxial magnetic gear hub motor was designed. The motor was compared and analyzed without cooling and with cooling system. At the same time, in order to meet the mechanical performance and lightweight design of the material, the static characteristics of the coaxial magnetic gear hub motor parts is comparative analyzed which is selected 45# steel and ZL101. The research shows that the armature without any cooling type can not be dissipated due to heat, so that the whole motor works in the high temperature environment. If the circulating water-cooled armature is used, most of the armature can be well cooled. Compared with 45# steel, ZL101 is selected as the material of the coaxial magnetic gear hub motor, in addition to meeting the requirements of mechanical properties, it can also meet the requirements of light weight.