In underground pipeline engineering, shaft jacking and reverse construction have become a vital construction method often selected by engineers because of their advantages of less disturbance to the surrounding environment. The design method is still too conservative compared to the traditional foundation pit support design. The key lies in the unclear grasp of the soil pressure change law of the supporting structure in the construction process and the unclear critical design height. Therefore, based on Terzaghi ‘s loose earth pressure theory, the calculation formula of loose earth pressure at any depth of the reverse construction shaft considering the inclined slip surface is given, and the theoretical method of the critical height of excavation during the construction period of the shaft wall of the reverse construction method is proposed. The research results of this paper are helpful for engineers in mastering the critical technical scheme of foundation pit support design and construction, which has significant theoretical and engineering application value.