With the in-depth study of nanomaterials, the field of nanotechnology has made explosive progress, such as nano-actuators and the energy storage applications research at the nanoscale. Here we report a detailed research of the torsional mechanical properties and energy storage of the spiral nanocone fibers (NF-s) through in silico studies. The torsional process was divided into three distinct stages with the change of NF-s deformation behavior, including the elastic deformation, plastic deformation and the finally complete destruction. The strain energy as a function of torsional angle of the first two stages is completely in parabolic form. The torsional rigidity, critical torsional angle and the limit of energy storage is found sensitive to the NF-s geometric parameters, the failure of NF-s due to the strain concentration is mainly governed by the inner radius. For the fixed apex angle, the load limit that the NF-s can withstand is increased due to the decreased inner radius, its yielding torsional angle can exceed 6 rad and the stored energy also increases significantly, which is not accessible from its counterpart with a normal cup stacked geometry. This paper provides a comprehensive understanding of the deformation and energy storage of NF-s, which should shed lights on the design of highly energy storage devices.