Intelligent automatic fire alarm device for building

The invention discloses an intelligent automatic fire alarm device for a building. The intelligent automatic fire alarm device comprises a mounting plate, a box body, a sound amplification cavity, a sound production mechanism, a trigger mechanism and a diaphragm shell, the box body is mounted on the front side of the mounting plate; the number of the sound amplification cavities is four, and the four sound amplification cavities are embedded in the top end of the box body from left to right in a clearance mode. The number of the sound production mechanisms is four, and the four sound production mechanisms are arranged on the inner sides of the four sound amplification cavities respectively. The trigger mechanism is arranged in an inner cavity of the box body; the number of the diaphragm shells is two, and the two diaphragm shells are embedded in openings in the left side and the right side of the bottom end of the inner cavity of the box body correspondingly. According to the intelligent automatic fire alarm