Abstract: In recent years, extreme weather disasters in Shenzhen have shown an increasing trend, and the requirements for preventing major risks of meteorological disasters are becoming higher and higher. In order to do a good job in preventing and responding to extreme rainfall, the Shenzhen Meteorological Department has reviewed and summarized the establishment of the "call response" and "343" mechanisms for emergency warning (three strategies for emergency warning release - strong pre warning reminders, small warning release units, and fast expansion of warning areas; four ways for emergency warning "call response" - "direct reporting" to city leaders, "precise" risk reminders, "fallback" automatic calls, and "closed-loop" supervision and implementation; three measures for emergency warning services - the entire network releases high-level warning SMS, high-frequency releases of precipitation real-time and short-term forecast information, and carries out "forecast+ science popularization" services throughout the process). From September 7 to 8, 2023, continuous heavy rainfall occurred in Shenzhen, breaking seven rainfall records since 1952, which is a sudden extreme extremely heavy rainstorm disaster beyond the city's flood control and drainage capacity. This paper introduces the application of the disaster early warning "call response" and "343" mechanism in the extreme extremely heavy rainstorm disaster and the linkage of department response, which provides reference for other regions to carry out disaster prevention, mitigation and relief work.