The invention provides a braking force distribution method and device for multiple units. The method comprises acquiring a target braking force of an entire train at present, wherein the target braking force of the entire train is the maximum braking force required to stop the entire train; acquiring a braking force capability value that can be applied by each unit of the entire train at present, wherein the braking force capability value of each unit includes a sum of an electric braking force and an air braking force that can be applied by all bullet trains and trailers in the unit; according to the target braking force and the braking force capability value of each unit at present, distributing a braking force target value of each unit on the basis of the load ratio of each unit, wherein the sum of the braking force target values of all the units is equal to the target braking force. By applying the method, the situation that the braking force difference between the units is too large when the bullet train or the trailer in a certain unit fails is avoided, so that the safe operation of the train is guaranteed.