In order to solve the problems of power signal characteristic analysis, feature extraction, modeling and testing standard of electricity meter encountered in the "three new characteristics" scenario of novel power system construction, this paper points out that the commonly-used load model cannot meet the requirements of testing the dynamic error of electricity meter, the definitions of power signal characteristics and current signal run length affecting electric energy metering are proposed. Accordingly, the strategy of establishing complex dynamic load combination energy reference signal model is proposed. The model reflects four typical characteristics of complex fluctuating load, which can shorten the test time and cost. Four types of problems in the feature modeling of power reference signal are proposed including feature acquisition, data preprocessing, characteristic analysis and extraction, and model use scheme. It aims to provide a complete strategy for the research and establishment of standards for the dynamic characteristic test methods of smart electricity meters.