Cold plasma exhibits broad applicability in the realm of fish sterilization and preservation. The combination process of plasma-activated water and dielectric barrier discharge (PAW-DBD) was optimized, and its disinfection effects on bass fillets were studied. The best conditions for disinfection of PAW-DBD were as follows. Bass fillets were soaked in PAW for 150 s, and then treated by DBD system at 160 kV for 180 s. The total viable count (TVC) reduced by 1.68 log CFU g . On the 15th day of refrigerated storage, TVC of PAW-DBD group was 7.01 log CFU g , while the PAW and DBD group exhibited a TVC of 7.02 and 7.01 log CFU g on day 12; the TVC of the control group was 7.13 log CFU g on day 6. The sensory score, water-holding capacity, and 2-thiobarbituric acid reactive substance values of the PAW-DBD group were significantly higher than those of PAW and DBD group (P < 0.05), whereas the TVC, Pseudomonas spp. count, and pH of the group were significantly lower (P < 0.05) during refrigerated storage. PAW-DBD treatment can enhance the disinfection effect, maintain good quality, and extend the storage period of bass fillets. © 2023 Society of Chemical Industry.