Based on the actual engineering project, this paper conducts CFD (computational fluid dynamics) numerical simulation on the ventilation scene of high-rise buildings based on FEM (finite element method) technology. Under the constraint variables of wind direction, outdoor temperature, floor height, etc., the air inlet temperature and outlet temperature are simulated by wind speed adjustment, and the air inlet temperature and outlet temperature are adjusted to the set range to ensure the normal operation of HVAC facilities under the condition of healthy and comfortable office environment.