Combination therapy is one of the potential strategies for tackling complicated tumor treatments like drug resistance. In this work, we have generated a therapeutic cisplatin-crosslinked albumin hydrogel (BC-Gel) that allows the local release of L-Buthionine-sulfoximine (BSO), cisplatin, and glucose oxidase (GOx) with distinct release kinetics. The BC-Gel with favorable biostimuli degradability and injectability could release therapeutic agents in a programmed manner within the tumor microenvironment (TME). The preferentially released BSO significantly suppressed the glutathione (GSH)-related cisplatin resistance and sensitized the tumor cells to cisplatin by inhibiting the γ-glutamylcysteine synthetase. Meanwhile, cisplatin achieved a sequential release and long-term treatment following the bioresponsive gel degradation under the combined action of chloride ions (Cl⁻) and proteinase in the body. In addition, the overproduced H₂O₂ of GOx-catalyzed glucose oxidation accelerated the depletion of existed GSH within cells and further weakened the cisplatin resistance, achieving enhanced tumor treatment together with a strong cell-killing effect. The above sequential drug release strategy based on the dual GSH depletion effect breaks the balance of the GSH-mediated redox TME and enhances the sensitivity of A549 cells to cisplatin forcefully, and provides a promising way for temporal control of drug release as well as efficient cancer combination therapy.