Security fence alarm

The utility model discloses a security fence alarm, press from both sides and the host computer including disc type support, goat's horn screw, arc, disc type support bottom is the disc base, and branch is equipped with at the center of base, and the host computer is fixed to the one end that the arc pressed from both sides, and branch is cliied at the arc position that the arc pressed from both sides to through the goat's horn screw fixation, the host computer includes identity identification card punch the card device, audible -visual annunciator, invisible formula laser probe and power, identity identification card punches the card the device and installs the afterbody at the host computer, audible -visual annunciator installs the top at the host computer, the front portion at the host computer is installed to invisible formula laser probe, the inside at the host computer is installed to the power, invisible formula laser probe includes invisible formula laser emitter and invisible formula laser receiver,