Many members intersect at the space joints with multi-annular plates,resulting in an intricate stress distribution. To examine the mechanical performance of high-strength space joints with multi-annular plates,a full-scale test was conducted on a high-strength Q690 SJC1 tension tower; subsequently,the finite element models of space joints at the varied slope locations and cross arms were established to investigate the mechanical performance of various loading protocols based on the adverse conditions,i.e. the strong wind,and then the space coupled effect was revealed. The analytical results indicate that: the locations of the ring plate or stiffened ribs connected to the chord members as well as the regions between the C-shaped insert plates and branch members display the larger stress under the adverse conditions of broken wires and strong wind. Therefore,strict measures should be adopted to ensure the quality of weld seams for preventing joint damage due to weld cracking; for the joints of varied slope locations and cross arms,the maximum stress respectively occurs in 99° and 90° directions of intersection regions of ring plats and chord members when all members are maintained in a constant loading ratio until the level of 250% under the strong wind loading; moreover,the space joints in the cross arms behave a higher security redundancy; the stress increases of intersection regions between the annular plates and chord members mainly distribute in the intersection of gusset plate along axes of branch members while altering the loading ratios between key members,in which the stress levels are positively correlated with the loads of branch members,and the intersection region between various branch members perform a slow stress increase.