The invention provides a braking early-warning device for an electric locomotive, and belongs to the field of speed measuring devices. The braking early-warning device comprises the electric locomotive, wherein a magnetic signal receiver is arranged at the bottom of the electric locomotive; a magnet is arranged on a wheel shaft of the electric locomotive; the output end of the magnetic signal receiver is connected to a counting device in a driving cab of the electric locomotive; the output end of the counting device is connected to a controller; a laser distance measuring device is arranged at the head of the electric locomotive; the output end of the laser distance measuring device is connected to the controller; and the output end of the controller is connected to a warner. The braking early-warning device disclosed by the invention can display the speed of the electric locomotive, and can warn before arriving at a braking point.