The invention discloses a steel rail grinding motor falling control method. The steel rail grinding motor falling control method comprises the steps that when steel rail grinding operation begins, whether a stroke sensor is subjected to breakdown or not is judged; if the travel sensor is judged to work normally, grinding motor fast falling, constant-speed reducing of downward-pressing force, adjusting and falling to the target stroke of the PI and falling to a steel rail at certain force operation are sequentially executed; if the travel sensor is subjected to breakdown, grinding motor fast falling, constant-speed reducing of downward-pressing force and falling to a steel rail at certain force operation are sequentially executed; whether the grinding motor falls onto the rail or not is judged, if the grinding motor does not fall onto the rail, return is executed; if the grinding motor falls onto the rail, the grinding start event is eliminated, and a grinding motor falling on rail markis arranged. The steel rail grinding motor falling control method can solve the technical problem that after an existing grinding motor conducts continuous grinding operation in constant-pressure falling control mode, resistance of a downward-pressing guide column of the grinding motor is increased due to much accumulated dust, the motor falling speed of the grinding motor is different, and the synchronization of a falling point of the grinding motor and the grinding effect of the initial section are affected accordingly.