The policies deployed by the government in Taiwan determine dramatically affect the development of a sector. In the past three decades, the high-tech industry has contributed to the prosperity of the economy for Taiwan. The focus of potential sectors includes green energy, optoelectronics, biotechnology industry, and agricultural science and technology industries. This study is to develop an enhanced assessment approach to evaluate candidate sites for building an optoelectronics factory. Traditionally, the assessment approach was conducted by ignoring the multiplicative effects of explored selection criteria in the real world. In order to resolve the above inadequacy on site selection assessment, fuzzy integral method (FIM) and consistent fuzzy preference relations (CFPR) were integrated to the proposed assessment approach to enhance the site selection assessment. Two optoelectronics sites were evaluated by employing the proposed assessment approach. The results through implementing the proposed approach not only could benefit decision makers to facilitate the site selection but also be more effective in real operations than tradition additive aggregate method. The results of the sensitivity analysis on FIM results were also more effective to plan the improvement strategies for the targeted site.