A method and a device for communication failure detection are provided. The method includes the following steps. Obtaining a piece of located path information of an unmanned vehicle. The piece of located path information indicates the unmanned vehicle is located at the located path of a plurality of paths in a route. Selecting one of a plurality of allowable periods as a located path allowable period according to the located path information. Setting a timer and starting the timer according to the located path allowable period. Under a condition that a communication module receives a periodic message before the timer reaches the located path allowable period, resetting the timer. Under a condition that the communication module does not receive the periodic message when the timer reaches the located path allowable period, determining that a communication failure occurs.