This paper descirbes the problems caused by excessive concentration of power such as instability of power invironment

the power supply pressure surge

idle power waste and so on in China.Based on given backround

in the paper we analyze how to use big data to practice dynamic power monitoring of smart grid

how to use the method of phase measurement unit（PMU）

adcanced metering infrastructure（AMI） and other key techonologies to optimize power system and improve the power supply quality and reliability.Besides

we also disscusse using real timefedback power consumption and price to control the power consumption in a stable range

which brings the advantages of improving the effi ciency of power network terminal

smoothing power load curve and reducing the load pressure and power loss effectively.