The invention relates to a wound dressing prepared by combining Ag/SiO2 hydrogel and sponge and a preparation method thereof. The wound dressing prepared by combining the Ag/SiO2 hydrogel and the sponge, provided by the invention, is prepared according to the following steps: dispersing polyvinyl alcohol in deionized water, stirring uniformly, adding an Ag/SiO2 powder after complete dissolution, and stirring again till the formation of a uniform mixture, namely the Ag/SiO2 hydrogel; then, uniformly coating a supporting layer with the Ag/SiO2 hydrogel, then combining with compressed sponge, covering an exposed part with a protective layer, freezing and thawing to obtain a finished wound dressing product. The wound dressing provided by the invention can effectively overcome the defects of the conventional hydrogel dressing, has liquid-absorbing, moisturizing, hemostatic and antibacterial functions, has low toxicity to human cells, can be effectively applied to clinical wound treatment, can effectively prevent infection caused by various bacteria or other microbes, reduces secondary damage to a patient, quickly promotes wound healing, and is an extremely excellent medical dressing.