The invention discloses a wheel derailment early-warning method. The wheel derailment early-warning method comprises the following steps of obtaining a vibration acceleration of a wheel; obtaining impact data of the wheel; obtaining vibration amplitude data of the wheel according to the vibration acceleration; and if the vibration amplitude data is larger than or equal to a first vibration amplitude preset value and the impact data is larger than or equal to a first impact preset value, outputting wheel derailment early-warning information. According to the wheel derailment early-warning method, early warning can be accurately made for derailment only by obtaining the vibration acceleration and the impact data; the whole process is stable and reliable; the number of the used data acquisition devices is small; the cost is low; and the application is easy.