1. Simple node form. The structure is simple and smooth, and can be applied to a variety of structural shapes. 2. High rigidity and good geometric characteristics. The wall of the steel pipe is generally thinner, and the cross-sectional turning radius is larger, so it has good compression and torsion resistance. 3. Simple construction and material saving. The pipe truss structure abandons the traditional connection components at the node and directly welds the rods, so it has the advantages of simple construction and material saving.The overall stiffness of the truss is ensured by controlling the maximum vertical deflection of the truss to not exceed the allowable deflection; the out-of-plane stiffness of the plane truss is poor and must be guaranteed by the support system. The space truss is composed of several plane trusses. The load can be decomposed into the component forces in the same plane as the truss and calculated according to the plane truss, or calculated according to the finite element method of the space articulated bar system. For the statically determinate truss in the ideal state, the axial force of the bar can be regarded as an unknown quantity, and the axial tension or pressure of the bar under a known load can be calculated by the numerical solution or graphical solution of statics (see static analysis of bar system structure).