The invention discloses substrate material based on surface-enhanced Raman technology and a preparation method thereof. The substrate material of the surface-enhanced Raman technology includes: a nanoinner core, which is composed of gold nano rods; and a nano outer shell, which is composed of nano silver material, and completely and completely covers a surface of the nano inner core. Vitamin K4 is bound to an outer surface of the nano outer shell. The substrate material is used as a probe of surface-enhanced Raman detection, detection sensitivity can be significantly enhanced, high-sensitivity detection of the KIM-1 content in urine is realized, and thus KIM-1 content determination of a large dynamic range is achieved.