Abstract: When solving the nonlinear equations of specific harmonic elimination of multi-level inverter, the traditional method at low switching frequency has the problems of difficult selection of initial values, the complex transformation of nonlinear equations, and it is easy to obtain local optimal solutions. A new harmonic elimination method for multilevel inverter is proposed. Firstly, the nonlinear equations are transformed by using the trigonometric function formula, and then constraint condition are assumed to transform the nonlinear equations into linear equations for solving. Taking five-level modified packed U-cells(MPUC) as the research object, exact solutions in 0,1.15 are obtained by combining the double-band SHEPWM control method with the new method. The new method is compared with the intelligent algorithm. The comparison shows that the new method has better total harmonic distortion rate(THD) under low modulation. Finally, simulation and experiment show that the new method can effectively eliminate the fifth harmonic of the five-level inverter.