The three-dimensional temperature and gas flow fields of transitional ventilation of closed henhouse with semi ladder coop were simulated with CFD software.In the simulation,the outdoor air temperature was 25℃ during the day and 13℃ during the night.The guide plates of side windows were provided with four different angles.Results showed that the angle of guide plate affected the uniformity of gas flow field and temperature field.The optimal angle of guide plates was found.The results of comparing the measured data with simulation showed that the relative error of gas velocity was 14.7% during the day and 11.5% during the night.The relative error of the temperature was 3.1% during the day and 3.6% during the night.The numerical simulation is in good agreement with the field measurement.It will provide a theoretical basis and guidance for the environmental control of the closed henhouse with semi ladder coop.