The traditional patent property appraisal method based on the cost method and income current method that is entering the information age today; it has neglected the elasticity of reconciling the item according to the environmental variation. On base of this characteristic, this article takes the traditional method as the foundation, introduces the sector price and corrective fixed price concept, establishes a brand-new fixed price model, carries on the quantitative assessment of the patent property in the trade process, and unifies various kinds of questions which the patent property appraisal involves, giving constructive suggestions to the key content of the corresponding appraisal system's, promoting the patent appraisal's development.