Automatic alarm fire extinguishing device

The utility model discloses an automatic alarm fire extinguishing device which comprises a sliding cover, the sliding seat is rotationally connected with a reciprocating rotating spray head, the reciprocating rotating spray head is provided with a first water spraying channel and a second water spraying channel which are symmetrical, and the first water spraying channel and the second water spraying channel spray water intermittently so as to drive the reciprocating rotating spray head to rotate in a reciprocating mode; and the alarm assembly comprises an impact ball arranged on the reciprocating rotation spray head. According to the automatic alarm fire extinguishing device provided by the utility model, when the mercury tube detects that the temperature is too high and bursts, the reciprocating rotation spray head can move in the sliding cover so as to liberate the first water spray channel and the second water spray channel, and at the moment, the first water spray channel and the second water spray channe