Theory analysis and experiments have been done to find out the factors which decide on the self-restoration speed of low remanence toroid cores. The results show that in the right working circuit, the core with appropriate pulse permeability can be restored to its remanence after excitation within 1 µs without reset current. Therefore, the toroid core restoration in a MHz repeat frequency, multi-pulse induction cavity is likely to be solved by choosing the right material of cores and use proper working circuit.