The invention relates to a mining high-low voltage reactive power and harmonic compensation device based on a compensation method, and belongs to the technical field of electrical testing equipment. The device comprises a busbar, a busbar transformer, an electric energy quality controller, a harmonic transformer T2, a voltage converter and a reactive power and harmonic generator, a high-voltage side of the busbar transformer is arranged on the busbar, a low-voltage side of the busbar transformer is connected to one end of the electric energy quality controller through an electric reactor I, the other end of the electric energy quality controller is connected to a low-voltage side of the harmonic transformer T2 through an electric reactor II, a high-voltage side of the harmonic transformerT2 is connected to the busbar through the voltage converter, the busbar is connected to the reactive power and harmonic generator through an electric reactor III, and a test object is connected onto the busbar. A testing structure is effectively simplified, testing efficiency is improved, and cost is reduced.