Temperature gradient is one of the most important factors which cause large deformation on large aperture optical element in inertial confinement fusion (ICF) drivers. In this paper,the ambient temperature around the switchyard was measured and the temperature distributing and changing characteristic with time was analyzed,which indicate that temperature changing trend inside of the switchyard is identical,and the temperature gradients of the uppermost part are higher than the bottom,and the temperatures of middle part are higher than the both sides. Loading the temperature on the finite element model of switchyard,gets the deformation of the optical element changing with time. The results indicate that temperature distribution has a great impact on the optical element,the change of mirrors can meet the request of target experiment when the switchyard has about 0.01 ℃ difference in temperature or about 0.1 ℃ partial difference in temperature.