This article presents the results of the numerical research on bolted flange joints in the field joint of trusses. A computational model was chosen for SCAD. The geometrically nonlinear calculation was made. The paper shows the correlation between stress and strain behavior of bolts and load intensity. Numerical results of the SCAD model calculation are compared with the results of the classical methods and ANSYS model calculation. The spatial stress-strain state of the connection is shown. The results of the study estimate the influence of bending moments on the stress-strain state of the bolts. The bending moments and rigidity ratio between different elements of the joints affect the load-carrying capacity of the bolts. The article is useful for engineers who are making calculations of tension flange joints.