The development of an injectable multifunctional hydrogel with tumor therapy, antibacterial treatment and wound healing properties is essential for simultaneously eradicating melanoma and promoting wound healing of tumor-initiated skin defects. Herein, iron ion-doped polyaniline (PANI(Fe)) tethered with guar gum (GG) chains is employed for the first time as a building unit for constructing a superior hydrogel (GG@PANI(Fe)-borax) crosslinked by borate/didiol bonds. Due to the dynamic and reversible properties of boronate ester bonds, the GG@PANI(Fe)-borax hydrogels had convenient injectability, rapid self-healing ability, and reversible gel-sol transformations under thermal- or pH-stimuli. More importantly, they took advantage of the second near-infrared (NIR-II) responsive photothermal conversion capability, accompanied by the photothermal-enhanced high cytotoxic ˙OH generation in the HO-enriched tumor microenvironment induced by iron-doped PANI. The as-prepared hydrogels exhibited excellent photothermal effects and controllable NIR-triggered drug release, leading to distinctly synergistic photothermal/chemodynamic/chemo-therapy effects of melanoma both (98.2%) and (98.8%). In addition, the obtained hydrogels also exhibited good anti-bacterial activity (>97.1%) against both Gram-positive () and Gram-negative () bacteria because they were based on PANI(Fe) and borax, which exhibit antibacterial activity. Furthermore, these GG@PANI(Fe)-incorporated scaffolds could improve fibroblast cell proliferation and angiogenesis for accelerating wound repair in tumor-bearing and infected wound mice. Taken together, GG@PANI(Fe)-borax hydrogels may be used simultaneously for eradication of skin-tumor cells, inhibiting infection and accelerating wound healing. This work offers an effective and facile strategy to fabricate an "all-in-one" multifunctional hydrogel platform for synergetic multimodal integrated therapy of tumors.