Abstract: Serving as a bridge between virtual models and physical entities，DT is regarded as a pillar of Industry 4.0 and a key driver of future innovation. The creation and utilization of digital twins span the entire lifecycle of physical entities. Under the context of Industry 4.0，digital twin technology has brought profound transformations to the mechanical field. This study first introduces the application architecture of digital twin technology，detailing its components across the physical layer，data layer，model layer，service layer，and application layer. Subsequently，it analyzes the key technologies of digital twins，with a focus on their optimization and application in industrial enterprises within the framework of intelligent manufacturing. Finally，the study applies digital twin technology to the mechanical manufacturing domain，explores the opportunities and challenges of DT adoption in this field，provides insights for the digital transformation of the mechanical industry，and prospects future development directions.