In order to study the effect of water content on the microstructure of high temperature and high pressure processing sea cucumber （HSC） body wall， HSC with different humidity ratio was prepared by vacuum drying method and then stored at 37 ℃. The effects of humidity ratio on the storage stability of HSC body wall were studied by the changes of TPA parameters， water status， SEM and TEM images. The results showed that the microbes and endogenous enzymes were completely inactivated. During the vacuum drying process， the collagen fibers gradually shrank and lost a large amount of water， resulting in the formation of dense network structures. During autoclaving， collagen fiber bundles and collagen molecules were destroyed. During storage at 37 ℃， they were further degraded， which were positively correlated with the humidity ratio. Therefore， the damage degree of structures could be effectively decreased by reducing the humidity ratio， extending the shelf life of HSC products.