This paper introduces the design scheme of the BIM-based energy consumption monitoring platform for ventilation and air conditioning of Lanzhou rail transit. The platform collects data for the station, including the energy consumption and operation status of environmental control equipment in large system, the station public area environment, passenger flow and outdoor weather. All data can be visualized through BIM, to monitor the real time energy consumption and cooling effect of ventilation and air conditioning equipment in large system. Meanwhile, the method of data analysis and processing is adopted to detect the monitored data. Taking the Dongfanghong Square station of Lanzhou rail transit as a pilot, this paper explores the optimal control method of ventilation and air conditioning energy saving, and realizes the effective combination of energy consumption analysis and optimal control, which will effectively improve the energy-saving management and control ability of environmental control system in urban rail transit operation stage.