The utility model provides a voltage sampling and conditioning circuit, which comprises a conversion circuit, an isolation circuit and a protection filtering circuit, and is characterized in that the conversion circuit comprises a plurality of resistors which are connected in series; the isolation circuit comprises a current transformer; the protection filtering circuit is connected with a secondary winding of the current transformer in parallel, a first port a clamping diode V35 is connected with a second port of a clamping diode V36, a second port of the clamping diode V35 is connected with a first port of the clamping diode V36, a third port of the clamping diode V35 is connected with one end of the secondary winding of the current transformer PT3 and a first end of an inductor L9, a third port of the clamping diode V36 is connected with the other end of the secondary winding of the current transformer PT3 and a first end of an inductor L10, and a second end of the inductor L9 and a second end of the inductor L10 are connected to sampling resistors respectively. The circuit provided by the utility model has functions of converting, isolating and filtering measured power grid voltage.