The aim of this research is to develop a workflow that integrates self-developed truss C# components, Karamba, and Galapagos for seeking optimized supporting positions in the truss system. This system proposes an instant feedback loop between design and structural rationality. The user could use this method to generate free-form surfaces with the rational structure supporting and structure simulation report for a design proposal. Due to the instant feedback of structure rationality outcome, possibilities of design and structure could be further explored and iterated. The optimization for supporting positions is based on the purpose of minimalizing the deformation (Karamba reformation parmameters) of the truss system which could maximize the efficiency of material, unit quantity, and labor resources.