The present disclosure provides an ion migration tube and a method of operation the same. The ion migration tube includes an interior space and an ion gate disposed within the interior space, the interior space includes an ionization region having an absolute value of potential V1 and a migration region. An ion gate is disposed between the ionization region and the migration region and includes a first ion gate grid having an absolute value of potential V2 and a second ion gate grid having an absolute value of potential V3, the migration region comprises at least a first migration region electrode having an absolute value of potential V4 and a second migration region electrode having an absolute value of potential V5. When the ion gate is opened, a potential well is formed for ionized ions between the first ion gate grid and the first migration region electrode so as to compress an ion group entering the migration region.