The dwell time and spin polarization (SP) of electrons tunneling through a parallel double δ-magnetic-barrier nanos-tructure in the presence of a bias voltage is studied theoretically in this work.This nanostructure can be constructed by patterning two asymmetric ferromagnetic stripes on the top and bottom of InAs/AlxIn1-xAs heterostructure,respectively.An evident SP effect remains after a bias voltage is applied to the nanostructure.Moreover,both magnitude and sign of spin-polarized dwell time can be manipulated by properly changing the bias voltage,which may result in an electrically-tunable temporal spin splitter for spintronics device applications.