This paper explores advanced analysis methods and construction techniques for long-span spatial structures in steel engineering. It delves into the principles of the Direct Analysis Method (DAM), emphasizing equilibrium, compatibility, plasticity, and stability, as well as load path and redundancy considerations. The DAM provides a robust framework for analyzing complex steel structures, ensuring stability, resilience, and efficiency. Furthermore, the paper discusses modeling techniques, including Finite Element Analysis (FEA), dynamic analysis, and nonlinear analysis, highlighting their significance in optimizing design solutions and predicting structural behavior under diverse loading conditions. Practical considerations in material selection, connection design, and construction are addressed, focusing on enhancing performance, durability, and constructability. Prefabrication and modular construction techniques are explored as effective strategies for accelerating project schedules, improving quality control, and enhancing site safety. Through a comprehensive review of literature and case studies, this paper provides valuable insights for engineers and researchers involved in the design and construction of long-span spatial structures in steel engineering.