Abstract: Through the monitoring on the deformation of the middle section and the left-right side section in the con- crete filled steel tube (CFST) support with the condition of uniform loading,as well as the strain and the ultimate bearing capacity of outer steel pipe and inner core of concrete,and combining with ABAQUS,a simulation analysis was conducted on the bending process with cohesive elements as the main research method in the constitutive model of concrete. This finite analysis method used the three-dimensional numerical simulation which displayed accurately on the whole progress of uniaxial compression experiment with CFST short column and core concrete test block in the mi- cro aspects. The actual morniting analysis shows that the bearing capacity of the support increases with the gathering of the thickness of the middle section and left-right side section in the range of a certain thickness for the letting pressure layer,which weaken the axial force of the support in the CFST arch and decreased with the deformation and destruction tempo of core concrete in the CFST support. There were some cracks appeared in the process of pressing,when the loading increased,the presence of cracks leaded to a concrete volume expansion,and then made the CFST short col- umn drum package. After reaching the ultimate load the yield of CFST circular arch was one of the hoop action failure of the concrete. Not only the boundary condition of different layer of the CFST support can lead a better understanding on the mechanical properties of CFST,also there is a certain engineering guidance significance to the non-dense pres- sure construction condition.