In view of the characteristics of dispersed site layout and complex risk points in aggregate production line , combined with a granite aggregate production line with an annual output of 3.70×10?m3, the design method and implementation process of the automatic fire alarm system are systematically elaborated. The production line covers the mining area and processing area, equipped with 7 electrical rooms and two fire pump rooms. A control center alarm system is adopted, with the main and subfire control rooms linked via optical fiber. The design follows eight current codes, with focus on selecting pointtype smoke fire detectors in electrical rooms and other key areas. The layout density is determined based on architectural parameters while considering the influence of structural beams. Cable-type linear heat detectors are employed in cable trenches, laid in a sinusoidal waveform to achieve continuous monitoring. Taking the E11A electrical room as an example, the planar arrangement of detectors, installation of heat-sensitive cables, and key points of module installation are described in detail. The system is also integrated with the emergency lighting system. The design has passed the fire protection review and provides a feasible technical reference for similar production line.