The poor penetration ability of antimicrobial agents limits their use in the treatment of intracellular bacteria. In this study, the conjugate CNC (6) was generated by connecting the cell-penetrating peptide Tat11 (1) and marine peptide N6 (2) via a cathepsin-cleavable linker, and the C-terminal aminated N6 (7) and CNC (8) were first designed and synthesized to eliminate intracellular Salmonellae Typhimurium. The cellular uptake of 6 and stability of 7 were higher than those of 2, and conjugates 6, 8, and 7 had almost no hemolysis and cytotoxicity. The antibacterial activities of 6, 8, and 7 against S. Typhimurium in RAW264.7 cells were increased by 67.2-76.2%, 98.6-98.9%, and 96.3-97.6%, respectively. After treatment with 1-2 μmol/kg of 6, 8, or 7, the survival of the S. Typhimurium-infected mice was 66.7-100%, higher than that of 2 (33.4-66.7%). This result suggested that 6, 8, and 7 may be excellent candidates for novel antimicrobial agents to treat intracellular pathogens.