Abstract: To meet the needs of the new structure construction，a new kind of cantilever support system is brought forward． Based on the system，it was built a finite element model taking account of the joint semi-rigid connection and generalized initial imperfections，whose correctness，practicability，security were analyzed and verified． In order to predict and treat the emergency in the construction of the system，its stress and strain were monitored and a further optimization of the new cantilever support system was also conducted． By the contrastive analysis of the finite element and the test results， the correctness of the finite element model and necessity of thinking about the influence of the joint semi-rigid connection and generalized initial imperfections were verified，which provided important reference and basis for the design and application of the cantilever support system．