The embodiment of the invention discloses a method and a device for processing the whole life cycle state data of a railway freight car. the accumulated mileage of the train running from the time of repairing to the time of failure is counted, and isassociated with the component information of each component, for example, the cumulative mileage is associated with the repair unit that repairs the component, so that each repair unit can be evaluated and the mileage that can be driven after repairing by a repair unit can be predicted. This method integrates the information of train failure and mileage, and can be used to analyze the relationship between the operation time of railway freight car accessories, mileage and maintenance unit.