Abstract: Deacidification treatment can eliminate the sour taste of the muscle of bonito (Katsuwonus pelamis), while its effect on the quality of bonito fish floss has not been explored. In this study, we applied different deacidification methods (Deacidification before processing, deacidification after processing) to treat bonito fish chunks, obtained pre-deacidified and post-deacidified tuna chunks, which were then processed into pre-deacidified and post-deacidified skipjack tuna floss respectively. Non-deacidified fish floss made from non-deacidified fish chunk was used as control. We compared the pH value, myofibrillar fragmentation index (MFI), and texture of fish chunks, as well as the pH value, puffiness effect (Floss content, fluffiness, net fluffiness, fine fluffiness, comprehensive score of puffiness effect), chromaticity, texture, and sensory characteristics (Acidity, morphology, color, impurities, softness) of fish flosses. The results show that deacidification treatment could increase the pH value of fish chunks and fish flosses, elevate the yellowness of fish flosses, and eliminate the sour taste of fish flosses. Deacidification before processing could soften fish chunk, deteriorate the puffiness effect of fish floss, increase the hardness of fish floss, reduce elasticity and cohesion, and lower the appearance quality. Deacidification after processing could reduce the MFI of fish chunk, increase the hardness, elasticity, cohesiveness and chewiness of fish chunk, and maintain the puffiness effect and appearance quality of fish floss. Deacidification after processing may improve the overall quality of fish floss by hardening the fish chunk. The results indicate that the deacidification after processing improves the overall quality of bonito fish floss by hardening the fish chunks and reducing myofibrillar degradation, thereby better maintaining the fibrous structure of the fish meat during the stir-frying process.