Instant controlled pressure drop combined drying technology, a creativity, environment-friendly, energy saving and high-quality drying method, has developed rapidly in recent years. Its dried products perform the characteristics of green and natural, good quality and rich nutrition, edible convenience, and broad application prospects. Firstly, the development research progress of instant controlled pressure drop technology at home and abroad were reviewed, and the differences of their equipment conditions and technical characteristics were compared and analyzed. The research progress of each part of the combined drying technology including pre-drying, pretreatment and instant controlled pressure drop were reviewed. The research status of the influence of key technical parameters of instant controlled pressure drop technology on product quality as well as the responding optimization strategy were emphasized. Besides, this paper described the current mainstream optimization strategy and its application in instant controlled pressure drop combined drying. A new process optimization strategy, namely dynamic optimization based on theoretical modelling was introduced. With the existed research results on water migration and quality changes during instant controlled pressure drop combined drying technology, the application prospect of dynamic optimization on combined drying process was analyzed. Furthermore, based on the characteristics and research progress of dynamic optimization, it was proposed that the dynamic optimization could be the guidance for instant controlled pressure drop combined drying process as well as the development of corresponding technology and equipment.