The evaluation of the operation condition of power transmission and transformation equipment is an important means to ensure the safe and stable operation of power system. The traditional state evaluation of power transmission and transformation equipment has bottlenecks such as incomplete state perception

low data quality

and difficulty in building evaluation model. Digital twin technology opens up the whole link process of entity-perception-modeling-application. Based on the new sensing technology

the comprehensive perception of the condition of power transmission and transformation equipment is realized. According to the operating characteristics of power transmission and transformation equipment

sensor device evaluation

and data in-depth governance are realized. Based on big data analysis

data mining and other technologies

the digital twin of power transmission and transformation equipment is constructed

which realizes the state differentiation evaluation

accurate fault diagnosis and accurate state prediction of power transmission and transformation equipment. The in-depth integration of digital twin and condition assessment technology will promote the operation and maintenance management of power transmission and transformation equipment to a smart era. This paper analyzes the application of digital twin technology in the condition assessment of power transmission and transformation equipment

and elaborates the specific application of digital twin technology including condition sensing

data governance

model construction

and application. The application status of digital twin technology in the condition assessment of power transmission and transformation equipment is summarized and discussed

and prospects in its future development trend are presented.