Joints are the most important parts of the space structure, the load-derormation curve (hysteretic curve) under repeated loading is the comprehensive reflection of their mechanical properties such as ductility, energy dissipation capacity, strength, stiffness and so on. By the simulation experiment analysis and the finite element simulation between the two models of hidden welding and no-welding hidden in K-type node in the chord axial reciprocating load resulted in the failure modes and hysteretic curve, the result of comparative analysis about finite elements is consistent with that of experiment study. The results show that the destroyment at hidden welding seam node is partly, the take-over is broken down at the welds finally. The welding line is destroyed overall when facing the destroyment of no-welding node. The carrying capacity of the hidden welding is obvious. Through the finite element simulation analysis instead of phase through node hysteretic performance test is feasible.