The utility model discloses a reactance compensation device and system, this reactance compensation device include the support and locate inductance main part on the support. The inductance main part includes an inductance coils, the 2nd inductance coils of relative up -down setting and locates two magnetizers between an inductance coils and the 2nd inductance coils. An inductance coils includes that first iron core and cover locate first winding on the first iron core, the 2nd inductance assembly includes that second iron core and cover locate secondary winding on the second iron core. Two the both ends of magnetizer equally divide do not with first iron core with the butt joint of second iron core is used for forming magnetic flow loop. Two the magnetizer with support sliding fit, the magnetizer slides and is used for adjusting magnetic flow loop's air gap to change magnetic flux, and then reach the effect of the inductance value of continuously adjustable inductance main part, be used for the adaptation by the withstand voltage test of examination article.