The project falls within the field of civil engineering, involving both civil engineering mechanics and the discipline of metal structures. The application of large complex steel structures in modern public buildings is becoming more frequent, and these structures are usually massive and complex systems. Traditional construction techniques and computational methods for construction simulation struggle to meet the needs for predicting the mechanical behavior during construction and ensuring safety control throughout the process, leading to occasional construction accidents with such structures. How to ensure the safety of the construction process and the quality of large complex steel structures, and to effectively control their construction process, is a hot issue that urgently needs research and resolution in the field of civil engineering. Based on more than ten years of experience in simulating the construction process of large complex steel structures, conducting real-time monitoring and data analysis on-site, the project team has conducted systematic theoretical research and extensive technical practice in construction process simulation analysis and monitoring and early warning technology for large complex steel structures. A series of innovative achievements have been formed. The main innovations are as follows: (1) Rigid large-span steel structure construction process simulation analysis method. Based on the stage-time varying characteristics of the construction process of large and complex steel structures, an improved step-by-step modeling method suitable for the simulation analysis of rigid large-span steel structure construction has been proposed, which solves the problem of matrix order transformation in different construction stages of traditional step-by-step modeling methods, and proposes reasonable principles for adding new components. For the overall hoisting construction of large and complex steel structures, a modified 'random guess' process analysis method for determining the reasonable position of lifting points has been proposed, as well as a calculation formula for the minimum number of lifting points required for the overall hoisting construction of spatial grid structures; for the asynchronous calculation problems during the overall hoisting construction process of spatial grid structures, The 'non-synchronism limitation' overall hoisting non-synchronization calculation process and the formula for calculating the differentials of lifting points during the hoisting process are proposed. (2) The construction process simulation and servo construction analysis method for cable-stayed dome structures. For the construction process analysis of cable-supported dome structures, an improved force finding analysis method based on initial strain as prestress input is proposed, and a corrected joint force finding + shape finding calculation method is proposed; a cable force tensioning analysis method based on temperature compensation and shape finding is proposed; for the anti-slip performance of cable support nodes in cable-supported domes, the concept of slip force density and the constitutive model of node slip are proposed. For wheeled prestressed steel structures, the principles for determining the pre-tension of spokes during the tensioning process are proposed. And proposed a matrix transformation analysis algorithm for real-time correction during the construction process of rotating installation for this type of structure. (3) Large complex steel structure construction process monitoring and early warning evaluation method. In order to achieve accurate and timely early warning evaluation of large complex steel structure construction systems and effective control over the construction process, for large complex steel structures, principles and methods for selecting key parameters for construction process monitoring were proposed, as well as principles and methods for static and dynamic measurement point layout; for missing monitoring data, a systematic method for compensating missing data was proposed; for the improved monitoring data obtained after compensation, methods for extracting representative values of monitoring data at each stage, as well as extraction methods for primary and secondary extreme points and important trend turning points, were proposed; methods for determining assessment parameters and early warning thresholds for large complex steel structure construction systems were proposed. The system proposes a two-level evaluation method for components and structures. The aforementioned research achievements have been successfully applied in the simulation analysis of construction processes and the monitoring and early warning of construction processes for a series of large complex steel structure projects, including Shanghai South Station, National Grand Theater, Chongqing Yubei Gymnasium, etc., ensuring the safety of each project's construction process and effective control over construction quality. Based on the above innovations, the project team has published 2 Chinese monographs and more than 40 papers, including 2 SCI-indexed and 7 EI-indexed articles; one software copyright has been approved.