A method for starting a vehicle and a related device are provided. The method includes: a server sends first security information and second security information to a mobile terminal and a telematics box respectively through an encrypted secure transmission channel or an encrypted secure transmission protocol, so that the telematics box can verify, by using the first security information and the second security information, a vehicle start instruction sent by the mobile terminal. When the verification succeeds, the telematics box controls the vehicle to start. According to the application, plaintext transmission of the security information between the mobile terminal and the telematics box is avoided, thereby avoiding leakage of the security information, and reducing a risk that the vehicle is maliciously started. In addition, a transmission process of the security information may not be restricted by a distance between the vehicle and the mobile terminal.