Abstract: In order to achieve a uniform distribution of nodal connection capacity of reticulated shell structures, to improve structural performance, and to enhance its ultimate bearing capacity, an index was proposed to measure the difference of the well-formedness between the structural nodes based on the structure vulnerability theory. Then the particle swarm optimization method (PSO) was used to optimize the cross-section size of structural members, in which the minimization of the difference between nodal well-formedness of structural nodes was taken as the optimization objective. In the optimization, constrains were considered such as the structural maximum displacement, the member slenderness ratio, the strength, and the stability of members. The results show that the defined difference coefficient of the structural nodal well-formedness can accurately reflect the uniformity of the overall stiffness of the structure. The uniform distribution of nodal connection performance can be realized by reducing the difference of the well-formedness of the structural nodes with the particle swarm optimization method to optimize the cross-section size of the structural members, the overall performance of the structure would be improved, and the failure model of the structure under earthquake has turn into the ductile failure mode.