Virtual assembly technology has been widely used in the fields of mechanical equipment and industrial simulations. However, the current virtual assembly is mainly centered on function and technology, without considering human interaction experience. Aiming at the realization, analysis and display of virtual assembly of large and complex mechanical structure, a complete set of technical solutions is introduced. 3D model establishment and assembly animation simulation are carried out based on UG and Tecnomatix platforms; Through VR technology, a human-computer interaction mode for structure-oriented virtual assembly process is built, which enables users to simulate the operations of assembly objects; Shutter 3D technology is used to output the experience picture of a single user in VR through a high-definition 3D projector, which can satisfy the immersive experience of multiple users in the 3D virtual assembly process at the same time. This technical route has a positive significance for simulating the assembly process of large complex mechanical structures more truly, verifying and improving the assembly scheme, and realizing the human-computer interaction oriented to the assembly process.