On the basis of combing and analyzing the latest research results of the extrapolation of the load spectrum of electromechanical equipment at home and abroad, this paper summarizes the research progress and comparative analysis of load extrapolation key technologies: time-domain load extrapolation, rainflow load extrapolation (parametric rainflow, non-parametric rainflow, and rainflow matrix extrapolations), and quantile extrapolation, in view of the load form and load characteristics of the electromechanical equipment during operation. In the context of the era of big data, the potential direction and development trend of the load spectrum extrapolation method in electromechanical equipment are discussed.