The invention discloses a contact totally closed contactor which comprises movable contacts, a movable contact bracket, a movable contact spring, fixed contacts, an armature, a base, a buffer spring, a static iron core and electromagnetic coils, and further comprises a housing, wherein the movable contacts, the movable contact bracket, the movable contact spring, the armature and the buffer spring are sealed in the housing; one end of each of the fixed contacts extends into the housing, and the other end thereof extends out of the housing; a magnetic transitional iron core is arranged between the housing and the base; and the lower end of the magnetic transitional iron core penetrates the housing to be in contact with the static iron core, and the upper end penetrates the housing to be protruded below the armature. According to the invention, the movable contacts, the movable contact bracket, the movable contact spring, the armature and the buffer spring are sealed in the housing, the magnetic transitional iron core serves as a magnetic field conduction mechanism, so as to isolate the interior of the contactor from the outside, which in turn avoids entering of dusts and other impurities; and accordingly, the spark generated during contact of the contacts can not ignite methane gas and other inflammable and explosive gases so as to avoid potential safety hazards.