As the climate change , the property of rock and soil changes accordingly with environmental temperature changes. In this paper, the influence of temperature field on the stability of the slope by some manifestation mechanism. The direct shear test of cohesive soil under different temperature conditions is carried out to explore the change law of cohesion and internal friction angle. Furthermore, combine ANSYS (finite element software) with the measured geothermal data to simulate the evolution temperature field of slope. According to the field of temperature , cohesion field is calculated which can find distribution of the safety factor by using optimized swedish method. Through a series of laboratory tests, it is found that the cohesive force of Xiashu is affected by temperature. Soil moisture content and density affect the soil showing thermal consolidation or thermal softening phenomenon. The evolution in temperature field of slope is simulated by ANSYS during the high temperature in summer of Nanjing suburb. The variation law of slope stability index is deduced. The results show that the slope stability is lower in summer hot temperature environment, and the safety factor of urban slope is lower. The heat island environment has a negative effect on the stability of slope.