We have investigated the periodic poling characteristics of MgO: LiNbO3 and properties of the domain wall velocity. Based on back-switching reaction, domain-inverted velocity can be accurately controled by multi-impulse electric field, which can be used to fabricate MgO: LiNbO3 with submicron uniform periodical structure. At the same time, we studied the cause of formation and the mechanism of submicron domain-inverted structure.