The invention relates to an electric meter dynamic evaluation system and method based on valley power analysis and solves the problem that, in the prior art, manual meter reading has the problem of long period and result lag, and a general electric meter can only obtain total power, and cannot obtain electricity consumption information of each electric appliance, and cannot carry out energy-saving analysis of each electrical appliance. The system comprises a meter end, a cloud service end and a user end. The meter end comprises a collection unit and a meter unit. The cloud service end comprises a calculating unit, a storage unit and an identity authentication unit. The method can calculate an estimated value of energy consumption per day through grey correlation analysis, and can carry out energy-saving analysis according to the estimated values. The method solves the problem that the general electric meter can only realize simple display of the energy consumption values, and allows users to know the specific energy consumption of each electrical appliance in detail; and the method can carry out energy-saving analysis of daily energy consumption information, so that the users can clearly know the energy consumption information, and adjust electricity consumption time or quantity in time according to the energy consumption or energy-saving information to achieve a better energy-saving effect.