Abstract: Alginate composite hydrogel is one of the research hotspots of tumor drug delivery system materials at present. Alginate hydrogel has good biocompatibility and regeneration properties. However, the natural alginate saline gel may not achieve the expected results in the body environment due to the slow degradation and instability of the gel. Alginate has found extensive application in cancer therapy through its combination with other materials and the utilization of ionic cross-linking, covalent cross-linking, and free radical polymerization to form hydrogels. Based on the composite system of alginate brine gel, this paper summarizes the structure and properties of alginate hydrogel, with a focus on recent research into alginate composite hydrogel in common cancer treatments application, summarizes the current research focus and discuss the existing problems of alginate composite hydrogel, so as to provide reference for further expanding the research of alginate composite hydrogel in clinical cancer treatment.