An approach for the optimization of hybrid welded I-beams based on the modification of the particle swarm method is proposed. A solution search is performed on discrete sets of variable parameters, which are taken as the size of sheets of rolled steel and steel grades. Depending on the values of the variables, a design of the support and ordinary stiffeners and their location along the length of the beam is performed. When varying the thickness of the sheets, the change in the design resistance is taken into account. As a mathematical model for calculating the stress-strain state, analytical expressions are used. To save the best solutions, the method of copying particles and their storage strategy in the database are used. This database is generated in accordance with the elitist principle, known in the evolutionary modeling theory. This makes it possible to obtain a high-performance optimization algorithm for structures of this type. The verification of the solution is performed using the finite element analysis.