The effects of salted duck egg white powder (SDEWP) and κ-carrageenan (KC) on autolysis and the properties of modori gel from threadfin bream surimi were investigated. The trichloroacetic acid-soluble peptide content (TCA-SPC) of surimi paste incubated at 65 °C for 60 min decreased significantly (P < 0.05) with the addition of more SDEWP. The decrease in TCA-SPC became lower in the samples incorporated with KC in a dose-dependent manner. Pastes containing SDEWP showed a more retained band of proteins with molecular weight of 45 kDa, while no change in protein pattern was observed when KC was added. The addition of SDEWP significantly improved the gel strength, water-holding capacity, and whiteness of the modori gel in a dose-dependent fashion. The more pronounced improvements in these parameters were observed when SDEWP was added in combination with 0.5 g/100 g KC. Modori gel showed significantly improved texture profiles when added with both SDEWP and KC. A denser and finer gel microstructure in modori gel was attained when added with both SDEWP and KC. Thus, SDEWP effectively prevented autolysis in surimi, while a combination of SDEWP and KC improved the gel properties of modori gel, in which maximal degradation of gel was induced by endogenous proteases.