The invention discloses a surface modification method of nano particles and the surface modified nano particles. The method comprises the following steps: adding neutral nano particles to be modifiedinto an anhydrous ethanol solution; mechanically stirring a first turbid solution obtained by mixing an absolute ethyl alcohol solution with the neutral nano-particles to be modified, and adding a surface modification modifier to generate a second turbid liquid; putting the second turbid liquid into an ultrasonic bath, and carrying out dispersion treatment to obtain a third turbid liquid; puttingthe third turbid liquid into a centrifugal machine, and carrying out separation to obtain a paste; washing the obtained paste with absolute ethyl alcohol, then placing the washed paste into a centrifugal machine, and carrying out separation to obtain a paste; and placing the paste into a drying oven after the paste is washed for three times, carrying out drying, and fully grinding the dried pasteto obtain the modified nano particle material. The surfaces of the neutral nano particles have lipophilicity, and the neutral nano particles can be uniformly dispersed in mineral oil, so that the phenomenon that the agglomeration phenomenon of the neutral nano particles in the oil is avoided.