The restoration of magnetic cores is very important to multiple-pulses linear induced accelerator(LIA). This paper describes how to restore LIA's cores between two pulses with interval less than 1 μs by the method of overlap restoration. The restore circuit is simple and effective; by covering the exciting pulses over a long inverted voltage pulse can form an inverted pulse between every two exciting pulses to restore the cores. The results show that the overlap restoration can effectively improve the efficiency of the magnetic cores worked multiple-pulses mode with pulse width less than 100 ns and interval more than 500 ns. In addition, the restoration has no dramatic effect on the accelerate pulses, which proves it is possible to reconstruct the single pulse cavity to the multi-pulse ca