In order to reduce the economic loss caused by postharvest deterioration of Lentinus edodes, based on instant controlled pressure drop puffing (Franch for Détente Instantanée Contrlée,DIC) technology, L. edodes was applied to develop non-fried L. edodes crisps. The effects of procedure sequence of osmotic dehydration (OD), osmotic agent types and mass fractions of OD solution, including 0,10%, 20%, 30%, 40% maltodextrin (MD), 10% whey protein isolate (WPI), and composite osmotic agents of 20% MD+10% WPI, on the average drying rate, total color difference, puffing degree, rehydration ratio, hardness and crispness of DIC dried L. edodes crisps were investigated. Low field nuclear magnetic resonance (LF-NMR) was used to investigate the effects of OD pretreatment on the water composition and status distribution of L. edodes. The results of procedure sequence of OD research showed that compared with the OD pretreatment before heat pump drying (HPD), OD pretreatment after HPD could significantly improve the puffing degree, rehydration ratio, crispness, and decrease the total color difference of L. edodes crisps (P<0.05). The results of osmotic agent types and concentration research showed that compared with the control group, OD pretreatment could significantly improve the puffing degree and rehydration ratio of L. edodes crisps (P<0.05), but the effects of OD pretreatment on the average drying rate, total color difference, hardness and crispness were dependent on the composition of osmotic solution. The optimal procedure was that L. edodes was firstly heat pump dried to moisture content of 70% in wet basis, and then OD pretreatment was performed with 20% MD+10% WPI. The OD treated L. edodes were subsequently pre-dried by HPD to moisture content of 35%±2%, and finally the equilibrated samples were performed by DIC. The quality characteristics of L. edodes crisps under aforementioned optimal procedure were superior. LF-NMR results revealed that after OD pretreatment, the transverse relaxation time (T₂) was shifted to the left and the amplitude increased with the increase of mass fraction of solute in the osmotic solution. Whereas the proportion of the free water was decreased but the bound water and immobilized increased. After HPD, except for 30% and 40% MD pretreatment, water in L. edodes was mainly comprised of loosely bound water and immobilized water, but the proportion of free water was very low (0.41%-4.67%). Compared with the control group, after HPD the proportion of free water (with the exception of 10% WPI pretreatment) and immobilized water in L. edodes was significantly decreased, but the proportion of loosely bound water was significantly increased (P<0.05). Pearson correlation analysis indicated that the OD pretreatment had greater influence on the quality of L. edodes crisps than HPD process, and the quality characteristics were closely related to LF-NMR relaxation parameters. The puffing driving force of L. edodes depended mainly on the immobilized and bound water especially loosely bound water, but it had nothing to do with the free water. This study aimed to provide theoretical basis and technical reference for the DIC technology of non-fried L. edodes crisps.