As architecture breaks away from traditional styles，grid structures with irregular spacing are in demand to meet construction requirements．An example of current architectural style is the Yadan sightseeing tower，which has an irregular double—layer steel grid roof．In this work，the engineering of such structures was reviewed and analyzed，and analysis and calculation of layered steel roof structures under seismic and wind 10ads were performed．The calculations assumed that part of the bar was damaged，and a damage assessment of the residual bearing capacity was conducted．Next，a finite element model that illustrated the 10ads imposed on the structure was built with analysis software．Then，a nonlinear time history analysis of earthquakes and a natural vibration analysis were done with the ANSYS finite element analysis software．Displacement curves showing the time history of key nodes and the stresses on key bars were obtained．Wind 10ad analysis using computer-aided design software of the space grid structure(MST2010)was done，and displacement and stress distributions were obtained．Last，the analysis results indicated that some of the key bars assessed preliminarily might be damaged，so a damage assessment of the residual bearing capacity of the structure was undertaken．The results showed that the irregularly spaced grid structure in this project can be adapted to the current trends in architectural style．The grid not only reflects current architectural style but also has excellent seismic and wind resistance performances，similar to those of the traditional spatial structure．Therefore，irregularly spaced grid structures are appropriate for use in similar projects with steel roofs．To assess earthquake response，the structure was subjected to structural vibration modes，and the weak parts were the head，tail，wings，and joints．Horizontal stiffness was greater than vertical stiffness．The structure was in a fully elastic state under the effects of multiple earthquakes；however，only a portion of the bar yielded under this rare earthquake scenario，and plastic deformation appeared in accordance with the basic principles of structural design．Parts of the bearing bars section should be increased at design time because it is a key member of the entire structure．Because a streamline design was adopted to resist wind，the design of this structure satisfies the requirements for wind resistance even in a hostile environment．In this study，the key bar calculations were very important to the bearing capacity of the structure．During structure construction and in service，great importance should be given to these bars．Once damage appears，the bars should be reinforced in a timely manner．The caseload design and analysis results can be combined for some practical projects，assuming some structural failure and through a method to evaluate structural residual strength to identify the key bars in the structure．Such projects would provide guidance for the structure's construction and later use．