To solve the inconsistency of comparison matrix in the Analytic Hierarchy Process (AHP), a new method is proposed. The inconsistency improving problem is equally converted to a optimization problem with constraints, which can minimize the modification of the original comparison matrix while reach the consistency requirement of AHP. In addition, the concept of allowable Interval is proposed to make sure the modification of elements in comparison matrix to be within the acceptable range. In order to minimize the modification, a method is designed to increase the allowable Interval step by step till the optimal solution is reached and the optimizing algorithm is realized by the improved pattern search method. An example is given to illustrate the feasibility of the approach. Compared with the present method, our approach is straightforward and easy to realize through computer programing, while truly find the improved comparison matrix with minimal modifications.