A mid-voltage variable-frequency driving system and a total harmonic distortion compensation control method are provided in this invention. The mid-voltage variable-frequency driving system includes a total harmonic distortion compensation unit. The total harmonic distortion compensation unit is used to perform an optimal adjustment on a reactive component reference value of a grid-side phase current, such that a harmonic component of the grid-side phase current may be reduced and a power factor of a three-phase switch-mode rectifier module within the mid-voltage variable-frequency driving system may be maintained.