This invention relates to a method for synthesizing non-aquo nanometer crystal zirconium dioxide. In this invention, C1-C4 organic acid (1) and zirconium isopropoxide (2) are used as raw materials with molar ratio of: (1):(2)=(2-10):1. After mixing, said mixture is put in a reactor, heating to 120-240deg.C for 10-24 hrs to obtain wet gel of zirconium dioxide, which is then washed by ethanol for 3-5 times, being dried under 100-160deg.C to obtain this inventive nanometer grade crystal zirconium dioxide product. This invention has advantages of: no aquo-system is needed for the whole productionprocess, this inventive hydrolysis needs no control, simple process, convenient operation, mild reaction condition, high yield, no environmental pollution, high value of side-products, high crystallinity, high pureness and narrow particle size distribution.