Aiming at the problem of equivalent conversion from conjunctive normal form to disjunctive normal form, an effective algorithm was proposed to construct reduction tree based on discernibility matrix.

An new concept of saturated conjunctive normal form is introduced and the nature of sat problem is studied for utilizing the characteristic of saturated conjunctive normal form.

Therefore, the optimization problem can be changed to normal quadratic programming form which can be solved by quadratic programming method.