The present disclosure relates to the field of shaft sealing, and particularly relates to a sealing structure of an electric-machine-shaft extension end. The sealing structure of an electric-machine-shaft extension end includes an electric-machine end cap and an electric-machine-shaft extension end, the electric-machine-shaft extension end is mounted to the electric-machine end cap via a bearing, a double-oil-seal structure is provided between the electric-machine end cap and the electric-machine-shaft extension end, the double-oil-seal structure includes an oil-seal seat that is connected to the electric-machine end cap and an outer-side oil seal and an inner-side oil seal that are provided inside the oil-seal seat, the outer-side oil seal and the inner-side oil seal are provided face to face, and are interference-fitted to the oil-seal seat, and an oil storing chamber and an oil-seal spacer ring contained inside the oil storing chamber are provided between the outer-side oil seal and the inner-side oil seal.