Abstract: Eriocheir sinensis gains wide popularity for its high nutritional value and distinctive savory taste. To investigate the effects of different sterilization methods on the quality and volatile flavor compounds in crab soup, Eriocheir sinensis was used as the raw material in this experiment. The effects of three different sterilization methods, namely pasteurization (PS), high-temperature sterilization (HS) and ultra-high temperature sterilization (UHT), on the physicochemical properties, flavor and other quality indicators of crab soup were analyzed. The results showed that all three sterilization methods reduced the total bacterial count to below the detection limit (<0.50 lg CFU/g). Moreover, UHT sterilization exerted the minimal impact on the nutrients, color, pH value, and in vitro digestibility of crab soup, better preserved amino acids in crab soup, and presented a taste profile most similar to the unsterilized group (NS). A total of 32 volatile compounds were identified by gas chromatography-ion mobility spectroscopy (GC-IMS). The volatile compositions of the UHT group were highly similar to those of the NS group. Based on relative odor activity value (ROAV) and variable importance in projection (VIP), eight key differential compounds contributing to crab soup flavor were screened out (VIP≥1). The key differential compounds in the NS group were anisole, tetrahydrothiophen-3-one, acetophenone and methylcyclopentenolone, all of which presented favorable flavor characteristics. Besides the above substances, γ-terpinene and 3-octanol with pleasant flavor were additionally identified as differential compounds in the UHT group. Heptanol and 2-octanol, categorized as off-flavor substances, were the dominant differential compounds in both PS and HS groups. The results indicated that UHT sterilization exerted the slightest impact on crab soup quality and could further enhance its desirable flavor. This study has important practical significance for promoting the processing and utilization of Eriocheir sinensis and improving the quality of sterilized aquatic products.