Abstract: This article proposes an efficient air conditioning room renovation and energy-saving operation and maintenance strategy based on the integration of BIM and IoT technologies. In response to the low energy efficiency of some old plant rooms in China, without replacing the air conditioning units during the secondary renovation, IoT dynamic control is achieved through 3D modeling to reduce system resistance and real-time data-driven variable frequency control, achieving a leap in energy efficiency. Through the case verification of the air conditioning renovation in a domestic commercial complex, the EERa of this method has increased from 2.8 to 4.4 after renovation, saving 470 000 kWh of electricity annually and achieving an energy saving rate of 31%. It provides a multi technology integration approach for the renovation of building equipment and energy conservation and emission reduction.