The invention provides a braking method and device. The braking method comprises the following steps of acquiring history braking information of a current vehicle; according to the history braking information, forming a transition probability matrix of a braking moment under every moment; according to the obtained transition probability matrix of the braking moment under every moment, obtaining a braking gear shifting decision-making table; and enabling the obtained braking gear shifting decision-making table to determine a target gearbox transmission ratio when the gear shifting operation is performed on a gearbox of the vehicle in the braking process of the vehicle. Through the adoption of the braking method and device provided by the embodiment of the invention, the downshifting frequency in the process of braking can be reduced.