The embodiment of the invention discloses a gear determining method, device, controller and storage medium. The gear determining method, device, controller and storage medium is applied to electric driven vehicles and belongs to the technical field of vehicle control. The method comprises acquiring the motor rotating speed and the motor torque of a vehicle at a first time, determining at least twogears according to the motor rotating speed and the motor torque, wherein the at least two gears comprises a gear of the vehicle at the first time and a gear adjusted and supported by the motor rotating speed and the motor torque; determining the respective loss power of the at least two gears, wherein the loss power is the loss per unit time of power output by a driving motor of the vehicle fordriving the vehicle; determining the one of the at least two gears, which corresponds to the minimum loss power, as a target gear, namely, determining a gear corresponding to minimum output power loss. The gear determining method reduces energy loss of the vehicle due to inappropriate gears, improves the energy utilization efficiency of the electric driven vehicles, prolongs the travel distance ofvehicles with fixed electric capacity and achieves energy-saving and range-extending effects.