In this paper, Fuzzy Logic Approach (FLA) is utilized to optimize the energy of thiophene-benzothiazole derivative Schiff base (C18H12N2OS2) molecule together with Density Functional Theory (DFT) calculations. The model has been established according to the theoretical results achieved by the DFT/B3LYP level of theory along with 6-31G(d) basis set on the Gaussian 09 program. We have constructed the continuous energy structure of the molecule depending on two torsional angles D1 (C15N1C3S2) and D2(C11C10C18S22) of thiophene-benzothiazole derivative Schiff base molecule. Thus, the constructed model is used to get the results for the untested data, and to obtain minimum energy value by conceivable time cost and great accuracy. Finally, we have shown that the FLA method gives reliable results for the optimization of the structure of the thiophene-benzothiazole derivative Schiff base molecule with minimum energy, when we compared our results with the DFT results using regression analysis.