With the rapid development of China's industry and manufacturing industry, the traditional maintenance methods of mechanical equipment gradually can't meet the requirements of high-efficiency production, and the demand for real-time monitoring of mechanical equipment operation status is constantly rising. In recent years, the development and application of digital twin technology provide a new idea for the monitoring of mechanical equipment operation status. This paper describes the importance of mechanical equipment operation status monitoring and the basic concept of digital twins, focuses on the analysis of the relevant theory of information fusion in the field of digital twins, combs the multi information fusion status monitoring technology, summarizes the advantages and disadvantages of each theory, and makes a comparative analysis. Finally, according to the research status of information fusion theory, the prospect is made from the application goal oriented construction of digital twin model, the exploration of intelligent model real-time update technology, and the construction of sensor digital twin model, which provides a reference for the research and development of digital twin driven mechanical equipment operation status monitoring technology in the future.