This study focuses on the "four-stage temperature" management requirements for crops in a solar greenhouse and takes the solar greenhouses in the Taiyuan area as the research object. A numerical model of a naturally ventilated solar greenhouse is constructed using the Computational Fluid Dynamics (CFD) method. The model considers the influence of crop resistance on indoor airflow, as well as the

transpiration of crops and the impact of soil evaporation on the thermal and humidity environment inside the greenhouse. The study investigates the movement of indoor airflow and the variation of temperature and humidity at different times during the spring season under natural ventilation and crop cultivation conditions.The results show that crops have a significant impact on the airflow field and temperature-humidity distribution inside the solar greenhouse. Under the condition of hot-pressure ventilation, the temperature in the crop area is within the suitable range for crop growth from 0:00 to 11:00 and 18:00 to 24:00. However, from 11:00 to 18:00, the temperature in the crop area becomes excessively high, which does not meet the temperature range required for the "four-stage temperature" management. From 0:00 to 21:00, the temperature and humidity in the crop area do not simultaneously reach the range conducive to disease occurrence, indicating a low risk of diseases. However, from 21:00 to 24:00, the temperature and humidity in the crop area simultaneously reach the range conducive to disease occurrence, which increases the likelihood of pest and disease infestations.