The invention relates to a ZnO nano-wire array synergistically modified by nano-Ag and TiO2 and a preparation method of the zinc oxide nano-wire array. The structure of the array is as follows: a ZnO nano-wire is taken as an inner core, nano-Ag is loaded on the surface of the ZnO nano-wire, a TiO2 film is modified at the outermost part of the nano-Ag, wherein the length of the ZnO nano-wire array is 10mum, the thickness of the TiO2 film is 5-10nm. The preparation method comprises the following steps: the ZnO nano-wire array is prepared by a hydro-thermal method, AgNO3 solution is taken as a precursor, nano-Ag is loaded on the surface of the ZnO nano-wire array by an illumination reduction method, then the ZnO nano-wire array is put into mixed solution of Ammonium hexafluorotitanate and boric acid, and the TiO2 film is formed on the surface of the array by an immersion method. The structure has the main purpose that the ZnO nano-wire modified by Ag inside a nanocable can be taken as an expressway for electronic transmission, and the light absorption is enhanced by utilizing the Ag surface plasmon resonance effect. The preparation method has the advantages that the cost is low, the process is controllable, and the repeatability is good, therefore, the preparation method can be applied to photo anode materials of a solar cell and can be also utilized in the photocatalysis field.