Abstract: Exploitation of mineral resources and construction of traffic facilities have led to the destruction of a large number of mountains, resulting in the formation of high and steep rock slopes, which have caused serious geological safety hazards and ecological function degradation. The ecological restoration of high and steep rock slopes is imperative. The key of slope ecological restoration is vegetation reconstruction. At present, there are still many problems such as lack of restoration theory and unclear reconstruction conditions. In order to clarify the relationship between the temperature and humidity fields and the plant growth in the rock slope, this study established a test site near Xiaodongshan in the city of Zhangqiu in Shandong Province. Multi-period monitoring experiments on the temperature and humidity field in the rock slope were carried out, the distribution characteristics of the temperature and humidity field in the rock slope are examined, and their ecological significance is analyzed in detail. The results show that (1) the atmospheric temperature causes the difference of the temperature variation in the monitoring hole in different seasons. In winter, the heat in the unsaturated zone of fractured rock mass is transferred from deep layer to surface layer, but in spring and summer it is opposite, The depth of the variable temperature zone ranges from 0 − 467 cm, and the depth of the constant temperature zone is greater than 467 cm. (2) In winter, the relative humidity in the slope first increases and then decreases with the increasing depth. In spring and summer, the relative humidity in the slope increases gradually with the increasing depth. (3) The water vapor saturated zone appears near the depth of 20 cm in winter, and begins to appear at the depth of 20 − 40 cm in summer and extends deeper. (4) The temperature and humidity in the rock mass are suitable for the growth of plants, and the plants are easier to survive if they are planted near the depth of 20 cm in spring. The results are of has important theoretical significance and application value for guiding the ecological restoration of rock slopes.