Fire alarm

The invention discloses a fire alarm. The fire alarm comprises an fire signal sensing device, an fire signal alarm device, and a flame retardant shell; the fire signal sensing device is composed of aflexible intelligent structure integrating driving with sensing and a Bluetooth emission module; the flexible intelligent structure is composed of a film module and a copper wire; the film module is composed of four layers of films which are a humidity-sensitive material layer, a gold electrode thin film, a piezoelectric material P(VDF-TRFE) layer and a gold electrode thin film layer from top to bottom; the film layers are mutually and tightly connected; the copper wire is adhered on the gold metal thin film by using silver colloid; the flexible intelligent structure converts temperature and humidity into electric signals to output through the copper wire; the Bluetooth emission module emits a fire signal under a power-on condition; the fire alarm device comprises a microprocessor, a powersupply, a Bluetooth recei