Compensating circuit used for measuring alternating voltage and provided with programmable capacitor array

The invention discloses a compensating circuit used for measuring alternating voltage and provided with a programmable capacitor array. The compensating circuit comprises a pair of first wires connected onto an alternate current circuit, an adjustable capacitor electrically connected onto the first wires and used for providing different capacitance values according to the programmable capacitor array, and a control unit electrically connected to the first wires and used for changing the capacitance value of the adjustable capacitor to the capacitance value of one capacitor in the programmable capacitor array according to an external order. As the capacitance value of the compensating circuit is changeable, an alternating voltage meter designed with the compensating circuit can measure the voltage in a wide frequency range.