The complete construction survey process of Taloon Tunnel in Iran is introduced in this paper and the key technology for the tunnel construction survey is described in detail. In order to change the usually adopted backward and complicated methods in tunnel settingout survey in Iran, a crosssection settingout survey programme based on programmable calculator is developed. This programme not only simplifies the crosssection settingout survey process, but also increases some rechecking conditions and reduces the probability of errors in calculation. The new technologies and methods used in tunnel construction survey in foreign countries are also discussed in detail.