The invention discloses a car sliding braking method, a car sliding braking device and a vehicle, and relates to the technical field of vehicle safety. The car sliding braking method includes the steps: receiving inclined angle data of the vehicle, judging whether a parking inclined angle of the vehicle is larger than or equal to a preset inclined angle or not according to the inclined angle data;reducing exciting current of a separately excited direct-current motor to preset exciting current when the parking inclined angle is larger than or equal to the preset inclined angle, and enabling anabsolute value of the preset exciting current to be larger than zero; adjusting the exciting current of the separately excited direct-current motor according to armature current data of the separately excited direct-current motor. The car sliding braking method can rapidly respond when car sliding happens, braking is implemented, and parking safety of the device is improved.