The utility model provides a portable correcting unit, is including setting up in the shifting beam of the pterygoid lamina top of case roof beam, and the shifting beam is box roof beam, and shifting beam upper end and lower extreme are provided with the connecting plate respectively, and two connecting plates pass through locking device to be connected with the shifting beam, and the both sides blind end of shifting beam is installed and is gone up screw matched with bolt with traverser, antifriction bearing and case roof beam side sliding contact are passed through to traverser one end, and the traverser other end is provided with the sliding plate of taking a plurality of screws, and the bolt on screw and the shifting beam cooperatees, hydraulic jack's hydraulic pressure cylinder body and traverser match. The utility model provides a portable correcting unit can solve the problem that work load is big, and the can be under normal atmospheric temperature simple, swift carries out correction and convenient operation to the box beam flange board.