A device and method for ferrofluid power generator and cooling system, wherein the waste heat of electronic device is used as a heat source to vaporize fluid and form bubbles as a forwarding pump of the ferrofluid. The fluid with magnetic nano particles is pumped forward and rotated by a fluid mechanism, then passes through a high density coil to result in the time varying magnetic flux and induced current. No additional heat-dissipating device is needed for this invention to dispose the waste heat, which requires the waste heat to produce electricity, which provides cooling and saves power.