Surgical excision is the main choice for tongue cancer treatment. However, the physiological functions of oral and maxillofacial regions might be severely impaired and high risk of tongue tumor recurrence cannot be avoided. It is thus becoming urgently important to develop alternative strategies for tongue cancer therapy. In this regard, a new class of near-infrared (NIR) light-responsive and peritumoral injectable hydrogel is fabricated with extraordinary photothermal therapy (PTT) for in situ tongue tumors. The as-prepared soft material exhibits good biocompatibility and ultra-strong photothermal effect due to the formed network by negatively charged proteins, chitosan molecules, and Ag AuS nanoparticles (NPs). In a well-constructed in situ tongue tumor model, tumors can be efficiently eradicated by one-time PTT treatment. Importantly, there are no side effects on surrounding normal tissues and potential tumor recurrence is inhibited. In stark contrast to traditional surgical excision, such biomaterials hold great potential for clinical treatment of oral cancers.