The invention discloses an intelligent energy-saving automatic control method of a dust removal system in a thermal power plant. The method comprises the following steps that a coal combustion amount,a coal ash content and a flue gas quantity of a unit are acquired in real time, then according to the fire coal amount, fire coal ash content and smoke amount of the unit, a set value Uesp of a secondary voltage U-electricity of a high-voltage power supply of an electric dust remover is calculated, and then the secondary voltage U-electricity of the high-voltage power supply of the electric dustremover is adjusted according to the set value Uesp of a secondary voltage U-electricity of the high-voltage power supply of the electric dust remover; and the actual smoke dust emission concentrationof an outlet of a wet-type electric dust collector is measured in real time, then a set value Uwesp (n) of U-wet electricity of the secondary voltage of the high-voltage power supply of the wet-typeelectric dust remover is calculated according to the actual smoke dust emission concentration of the outlet of the wet-type electric dust remover through a PID mode, and then according to a set valueUwesp (n) of the secondary voltage U-wet-type electric dust collector of the high-voltage power supply of the wet electric dust remover, the secondary voltage U-wet-type electric dust collector of thehigh-voltage power supply of the wet-type electric dust remover is adjusted. According to the method, the high-voltage power supply of the electric dust remover and the high-voltage power supply of the wet electric dust remover can be efficiently and efficiently operated under different working conditions.