The present invention discloses a residue-discharging and degreasing process for fishbone peptide pretreatment, including the steps: 1) boiling: boiling a raw material, filtering, and crushing; 2) pressing: pressing to remove part of fat; 3) rinsing: adding purified water at 90 DEG C, stirring, rinsing and filtering; 4) thermally treating: adding hot purified water, stirring, and heating to form a slurry; 5) enzymatically hydrolyzing; adding alkaline protease, neutral protease, composite protease and flavoring protease for enzymatic hydrolysis; 6) residue-discharging; standing, and pumping supernate to a liquid storage tank by a pump; discharging the bottom slurry out of the liquid storage tank; 7) centrifuging: filtering and centrifuging a liquid to separate the liquid. By subjecting salmon material to residue-discharging and degreasing, the raw material is freed from fishbone residue and has a fat content down to 0.1%, the prepared salmon bone peptide is better in taste, the extracting process is simple and more efficient, extraction reprocessing of the salmon bone wastes is greatly promoted, and more economic valve can be created.