A control method and apparatus for a single-phase five-level converter are provided. The method includes: obtaining a first-phase initial modulated wave and a second-phase initial modulated wave of the single-phase five-level converter; obtaining a first-level modulated wave, a second-level modulated wave, a third-level modulated wave, a fourth-level modulated wave, and a fifth-level modulated wave that are output by the single-phase five-level converter; calculating the first-level modulated wave, the second-level modulated wave, the third-level modulated wave, the fourth-level modulated wave, the fifth-level modulated wave, the first-phase initial modulated wave, and the second-phase initial modulated wave, to obtain a common-mode modulated wave of the single-phase five-level converter; and calculating the first-phase initial modulated wave, the second-phase initial modulated wave, and the common-mode modulated wave, to obtain a pulse-width modulated wave of the single-phase five-level converter. Implementing the embodiments of this application can increase a system response speed and improve system reliability.