This application relates to the mobile communications field, and in particular, to a random access technology in a wireless communications system. This application provides a method for sending a random access preamble sequence, an apparatus, and a system. In this solution, a terminal device obtains a cyclic shift value that satisfies a high-speed movement scenario and sends a random access preamble sequence corresponding to the cyclic shift value. Impact brought by the high-speed movement scenario is considered when the random access preamble sequence is determined, thereby avoiding interference between terminal devices in the high-speed scenario.