Abstract: With economic development and to meet the needs of social progress， complex steel structures have been widely used in large public buildings such as stadiums， stations， and airports. A mechanical simulation analysis of the construction process was carried out for the complex steel structure project of the Qingdao Virtual Reality and Enjoyment Center. The structure features an inverted conical spatial grid-trussed tube with a steel frame. The characteristics and key techniques involved in the five key construction steps of the complex steel structure project were analyzed. In addition， the grid-tube-truss system was simulated with MIDAS/Gen software during the pre-construction phase. According to the construction scheme， the construction process was mainly divided into 12 steps.The deformation and stress of the structure at each construction step were studied through a mechanical simulation of the entire construction process. The results demonstrated that the structure’s behavior met the limit requirements of Standard for Design of Steel Structures（GB 50017-2017）， thereby providing support for ensuring structural safety during construction. Finally， key and difficult aspects in the construction of the complex steel structure project were analyzed， and corresponding control measures were put forward， wproviding a reference for safe construction.