The paper proposed the optimization of the network construction timing of the control network according to the specific conditions of the survey route. Moreover, presented here are the adjustments according to the layout requirements of the control network layout process, strengthening the control of the line level base point during the construction process. Several optimization solutions are discussed for the special design of the level control before the construction of the long tunnel. It has been explained the methodology to introduce new Continuously Operating Reference Station (CORS) technology in railway survey and design with appropriately adjustment of the position requirements of the control network according to the specification. In order to carry out the special design of the levelling route with precision, it is advisable to set a certain stable reference point in the level control of the long line. The proposed methodology can effectively solve some problems existing in the current high-speed railway construction process, and make the precision measurement control network better for survey, design, construction, supervision and operation.