The invention relates to an operating mechanism for a three-working position switch, which solves the problems of large motor output inertia, low running speed, a small number of output interfaces, no automatic locking or automatic releasing function during manual operation and easy faulty operation due to the absence of an electromagnetic clutch and a direct driving auxiliary switch in the conventional operating mechanism for the three-working position switch. The operating mechanism is characterized in that: a transmission system consists of a chain transmission group, a bevel gear group and a screw rod driving group; the electromagnetic clutch is connected in series between a motor and a shaft coupling; and an auxiliary switch, a manual mechanical clutch device and a mechanical interlocking device are arranged on a mounting plate. The operating mechanism has the advantages of compact structure, reliable action, small operating force, complete mechanical and electrical interlocking functions during electric and manual operation, capability of preventing faulty manual operation and high running speed. Moreover, the direct driving auxiliary switch is provided, so that the operating mechanism is provided with more output contacts, can meet the requirements of multi-contact users in an electric power system and brings great convenience to users.