The diffusive ventilation subgrade exhibits excellent active convective heat transfer performance and is widely applied in the field of special structural subgrade engineering in permafrost regions. However, under the extreme environment of high altitude and low temperatures, existing technical solutions often encounter challenges such as temperature control failure, rapid battery degradation, frequent maintenance requirements, and limited system intelligence during long-term operations. To address these issues, this paper proposes a diffusive intelligent temperature-controlled ventilation duct group control system based on integrated energy management, along with its corresponding cooling control methodology. The system utilizes wind-solar hybrid power generation system to achieve energy autonomy. By implementing a distributed architecture combined with cloud server technology, a one-master multi-slave intelligent temperature control system has been established. Through real-time monitoring of internal and external temperature and humidity data within the subgrade pipe network, the operational strategy of the blower is optimized. This enables precise adjustment of the subgrade temperature field, which ensures the thermal stability of the subgrade and effectively reduces the risks associated with permafrost thawing and subsequent settlement. Experimental results show that the proposed system is feasible, which can significantly enhance the temperature control accuracy and operational reliability of the ventilation duct group in extreme environments. Furthermore, the system achieves automatic alarms and remote intelligent operation for temperature-controlled subgrades, which provides efficient, intelligent, and energy-self-sufficient technical support for the long-term stable operation of permafrost subgrade.