This invention relates to a negative energy generating device, which includes the power fixed on the undercarriage and the runner inside the end face with several motors fixed longitudinally along the axis as the equal angle, wherein the runner is fixed on one radial of the hub's external radial, the middle part of the hub's external radial has several conductive loop fixed separately by the dielectric cirque, the other end of the hub's external radial is fixed with the passive gear, the hub is fixed at the middle part of the main axis's external radial by the bearing, and one radial of the main axis's external radial is fixed with the traveling gear, the two end of the main axis are fixed by the screw at the top of the frame, and the bottom of the frame connects fixedly with the undercarriage, the power drives the runner rotating by the variable-gear device that is composed of the driving gear and the passive gear, several gears at the axis end of the motor's rotor join with the traveling gear of the main axis and have two speed hefts running, which can make the kinetic energy of the rotor more the power energy, so that the motors turn the negative energy into the current input load, this invention can be used as the power for small-sized electricity consumption device.