Complex decision-making problem discussion in hall for workshop of metasynthetic engineering (HWME) requires that the experts` qualitative opinions should be converged in the end. To investigate the problem of how to converge their opinions, an approach of expert group discussion is proposed on the base of the model of interactive genetic algorithms, in which expert group thought and the computer technology are integrated tightly and the mutual recognition of community opinion is reached. Practices show that the optimal solution of complicated decision-making problem is obtained easily, and the approach is effective and in accord with the practical discussion process.