The invention discloses a preparation method for a silver-zinc oxide nano-composite structure. The method is simple, efficient and environmentally friendly. The method comprises the steps that the characteristic that electric charges carried by zinc oxide and electric charges carried by nano-silver are opposite is utilized, and nano-zinc oxide powder carrying the positive electric charges is added into nano-silver sol with the negative electric charges in a certain proportion; ultrasonic dispersion or mechanical agitation is performed, so that the nano-zinc oxide powder and the nano-silver sol are fully mixed; on the basis of electrostatic interaction, nano-silver particles are loaded onto the surface of the nano-zinc oxide; afterwards, the obtained solid product is separated through centrifugation or filtration, and the solid product is washed several times with ethyl alcohol and dried to obtain the target product. The preparation method is simple and easy and convenient to implement, the range of the raw materials is wide, neither a surface active agent nor a molecular coupling agent needs to be added, the method is low in energy consumption, free of pollution and environmentally friendly, the product is even in load, the size of loaded silver particles and the amount of load can be regulated and controlled, the interface is clean, and the method is beneficial to accurate regulation and control over the antibacterial activity, photocatalytic properties and surface-enhanced Raman scattering properties of silver-zinc oxide nano-composite structure.