The utility model discloses a low voltage winding's winding inner tube structure, low voltage winding twines the one multilayer coil that forms by the electromagnetic wire, and the multilayer coil twines on the winding inner tube, the winding inner tube includes opening steel cylinder, epoxy plate and calico area, set up a breach along its axial on the vessel walls of opening steel cylinder, the epoxy plate shutoff on the breach and with the opening steel cylinder forms the steel cylinder of remaining silent, the calico tape winding winds the remain silent outer peripheral face of steel cylinder. The utility model discloses a low voltage winding's winding inner tube structure, simple structure can put forward the ability to withstand short circuit of distribution high voltage transformer.