Inrush current impact on the safe and stable operation of power systems for offshore oil platforms. Because of the protection of their initiation malfunction switch tripping， power shock， It has been very concerned about the problem electrician. This article analyzes the causes of inrush current generated， when the transformer pressure by controlling the magnetic circuit is not saturated to suppress the magnetizing inrush， the suppression strategy is to take points off control switch in the same time in the early phase of the applied voltage， to ensure the presence of residual magnetism magnetic bias offset opening formed after closing.