1. A portable charging device with kinetic energy recovery, comprising a machine body, a kinetic energy recovery component, an alternating current-direct current (AC-DC) electric energy conversion component, and an energy storage component, wherein the kinetic energy recovery component is embedded in the machine body by a locking assembly; and the kinetic energy recovery component comprises a ring body, a conductor coil, a permanent magnet sphere, and two sealing covers, wherein the ring body is oval, the two sealing covers are symmetrically and fixedly attached to both sides of the ring body, and a middle part of the ring body and the two sealing covers form a vacuum cavity; the permanent magnet sphere is able to reciprocate up and down in the vacuum cavity; the conductor coil is a wire and is symmetrically, fixedly and hermetically wound on both sides of the ring body; both ends of the conductor coil are electrically connected with two first conductive blocks; the two first conductive blocks are fixedly embedded in the ring body; the energy storage component is arranged at the right side of the machine body; the AC-DC electric energy conversion component is arranged at a bottom side of the machine body; and the two first conductive blocks are electrically connected to the AC-DC electric energy conversion component.