Scheme of reversibility of entangled system. Employed by the D-J-C model to investigate the reversibility of entanglement system after weak measurement and reversible operation. Cavities 1 and 2 form a D-J-C model. Cavities 3 and 4 form the other D-J-C model. We only select one path to perform the process. Such as path 1, in cavity 1 we place a detector to make a weak measurement and subsequently make reversible operation in cavity 3.