An integrated fire alarm method includes receiving a preliminary detection signal from a preliminary detector, and comparing the preliminary detection signal with a predetermined corresponding threshold; controlling a notification device to issue an early-warning notification if the preliminary detection signal is greater than the corresponding threshold; receiving a primary detection signal from a primary detector after issuing the early-warning notification, and comparing the primary detection signal with predetermined corresponding threshold; and controlling the notification device to issue a formal notification if the primary detection signal is greater than the corresponding threshold.