The temperature response of steel truss structure is affected by the boundary conditions. If the stress caused by temperature cannot be completely released, the structure may be damaged. In order to deeply reveal the laws of temperature and steel truss structure under different boundary conditions, this paper studied the influence of temperature on steel truss structure under different boundary conditions through experiments. First, the temperature effects on a sample member under different bearing stiffnesses were investigated using the stiffness method. Second, a truss structure finite element model was built to study the temperature response. The results indicated that the maximum axial stress of the member significantly decreased when the boundary condition of the structure was transferred from the fixed to a roller bearing.