Nowadays, the development trend of the global smart grid is swift and violent and its core technology is gradually improving.At the same time, the Chinese government devotes develop smart grid in order to stimulate the economy.Smart meters due to is very close to the life ofthe vast number of consumers living with electricity, so its application technology is also widely popular among residents.Through the development of smart grid, smart meter has been quite popular as its smart terminal.In addition to a number of basic power calculation functions, they have some more new intelligent functions in order to apply to the development of new energy and the requirements of smart grid, which is different from the previous use of the meter,such as bidirectional data communication, the control technology of user side, multiple rate twoway metering and anti powerstolen etc.In this paper, the measurement method of single phase intelligent electric meter is studied.The voltage and current signals transform analog signals to digital signals by means of the high precision analog to digital converter. Then, the signals get through the high pass filter and the sampling filter, filtering out the DC gain and high frequency noise,then they can get the required voltage and current sampling data.After the voltage and current data are multiplied, the instantaneous active power can be obtained,and the average active power output gets through the low pass filter output.In addition, the voltage and current sampling data can get the effective value of voltage and current through the square circuit, low pass filter and square circuit respectively. The active power can be obtained through the integration of time, and the active energy can get.