Abstract: As an important index of power quality, flicker directly indicates the voltage quality of power supply. Based on the design specifications for flickermeters published by the International Electrotechnical Commission (IEC), the mathematical model and digitalization of flickermeter were discussed in detail. Simulation was conducted and the results showed that the digital method fully satisfies the IEC standard. A flickermeterwas designed based on virtual instrumenttechnology, and ithase been used in electric railways.