Abstract: This paper focuses on the automatic control issues of major auxiliary equipment trips under lowload conditions for thermal power generating units, conducts research on lowload auxiliary equipment control optimization technology, and proposes a complete set of control schemes for smooth transition during lowload auxiliary equipment trips. By analyzing the dynamic characteristics of the units after key auxiliary equipment such as coal mills, induced draft fans, forced draft fans, primary air fans, and steamdriven feedwater pumps trip under low loads, an emergency control strategy based on multivariable coordinated control is designed. A parameter adaptive mechanism that adapts to different boundary conditions is established, and a complete lowload auxiliary equipment control optimization system architecture is constructed. Research shows that this technical solution can enable the units to automatically, rapidly, and smoothly transition to a new stable state when major auxiliary equipment trips under lowload conditions, effectively avoiding unit trips, significantly reducing operator intervention, and improving the operational reliability and safety of the units during deep peak shaving periods.