Indoor environment comfort directly affects the health and work efficiency of staff in the room. Effective control is needed to ensure its comfort. Taking a certain office as the research object, this paper proposes a Monte Carlo adaptive control method based on the policy to optimize the control of air conditioning system, humidifier, dehumidifier, lighting system and ventilation system in the building and adjust the indoor temperature and humidity, illumination and CO2 concentration to improve indoor comfort. The mathematic model of the change of the factors affecting the comfort of the indoor environment is set up, and the model is validated by the experimental data. At the same time, the simulation and comparison with the PID and fuzzy control algorithms are carried out. The results show that the On-policy Monte Carlo control method can track the actual situation better while controlling a number of factors that affect the indoor environment at the same time. The steady-state error of this method is small and the convergence speed is fast.