With the increasing railway transportation demands, railway operators need to enhance the capacity in high traffic corridors to improve transportation efficiency. The establishment of the concept “virtual coupling (V C)” provides an effective method for achieving higher capacity. The core idea is to reduce the train separation and to enable a maximized number of trains on the track. Based on the emerging modern communication techniques, the synchronous operation between different trains to form the coupled state can be achieved without any physical connection. In this paper, a following-train speed profile optimization model is proposed by employing Mixed Integer Linear Programming (MILP) approach to achieving V C with the leading train. Therefore, the safety constraints (i.e. moving block signaling (MBS)) are considered as the most important physical border between each train under the VC operation. Three cases under different scenarios are conducted on a generic high-speed rail, which proves the effectiveness of the proposed method on the speed profile optimization for following trains under the V C operation. It also shows the factors influencing the time headway under minimized -separation operations.