The utility model relates to a join in marriage power -grid switch technical field, a low pressure three -phase bistable state permanent magnetism air switch, it includes the insulator foot, install first insulation support and the 2nd insulation support respectively in the left and right sides of insulator foot, the wire winding frame foundation is on first insulation support and the 2nd insulation support, it keeps the permanent magnet to install in first annular, keep the permanent magnet under installing in the third annular, the insulating contact connecting plate that be located the bobbin outside is had at the bottom of slip iron core fixed mounting, there is one to move down a set of quiet contact - piece set that shi nengyu the corresponds movable contact spring that contacts at the slip iron core at insulating contact connecting plate bottom fixed mounting. The utility model discloses rational in infrastructure, consumption of electric energy divides closing coils to need notlong -time work for a long time, has effectively solved long -term circular telegram of coil and has leaded to generating heat, existing the problem of potential safety hazard, and the noise that hassent when having reduced the permanent magnet continuous operation reaches the influence to magnetic field, has reduced the energy resource consumption, and safety ring protects.