Abstract: To overcome the shortcoming of single-key-lock-pair access control scheme at present, a new single-key-lock-pair access control scheme is proposed, based on the property that a integer can be denoted into only one binary digital. All the single-key-lock-pair access control scheme are threaten by overflow problem. Besides that, under old scheme, user can own several kinds of right on one file only based on the supposition that the access rights is increase by degrees. With perfect dynamic feature, the new scheme is simply realized. Under new access control scheme, user can own several kinds of access right upon one file under the new scheme without the supposition that the access rights is increase by degrees, and the possibility of overflow problem is significantly reduced by our new method.