A high efficiency approximate DCT circuit based on multiple voltages was designed. By approximating the arithmetic units and coefficients in DCT, the energy consumption of DCT was reduced by logic simplification. To further improve the energy efficiency of the approximate DCT circuit, low-voltage supplies were used in some cells of DCT, so the circuit achieved lower energy consumption while maintaining the circuit performance. Based on 018 μm CMOS technology, the results showed that the energy consumption of the proposed method was reduced by 314% and 138% compared with the same circuits at standard voltage and low voltage, respectively, while keeping same frequency as the standard design. Compared with the traditional approximate CORDIC DCT design, the circuit reduced the energy consumption by 447%, while providing 14 dB higher output accuracy than the traditional approximate CORDIC DCT circuit.