The nodes of the composite frame structure are the key parts for connecting and transmitting forces between prefabricated concrete columns and steel beams. The overall stability of traditional prefabricated frames is weak, and instability defects are prone to occur under stress due to the problem of strong and weak axes. In order to improve its seismic performance and significantly enhance the required ductility of components, this paper combines the improved ant colony optimization (ACO) algorithm to study the optimization design of seismic performance of composite frame structures. Firstly, based on parameter adjustment, an improved ACO algorithm model was constructed, and then the seismic performance of the frame structure was designed and analyzed, including optimization methods for structural layout, component design, and connection methods, effectively improving the seismic performance of the composite frame structure.