Abstract: This paper introduces the physical and chemical properties of the inactive nitrate powder, its solubility to the formation and the difference from the conventional acidizing technology, analyzes the stimulation factors of the acidizing technology of inactive nitrate powder mixed acid. Field test indicates:when the nitrate powder is used together with other acid, it can enlarge the acidizing area, reduce the acidizing cost, at the same time effectively reduce the secondary contamination of the formation. This paper discusses the particular role played by the inactive nitrate powder during acidizing. This technology is simple and convenient in operation, and the stimulation effect is obvious.