The invention discloses a preparation method of micro-doped high-surface-area nano-zirconium dioxide powder. According to the preparation method, zirconium nitrate and lanthanum nitrate are taken, water is added to prepare a mixed solution, then hydrazine hydrate is added, a six-position magnetic stirring device is adopted for uniform stirring and mixing, and then a dilute nitric acid solution isadded; the solution is contained in a high-pressure reactor, the temperature is maintained in a turbulent atmosphere constant-temperature drying oven, and a complex reaction of a precursor is completed; the solution obtained after the complex reaction is filter-washed, dried and contained in an electrically-controlled high-energy ball-milling device for ball-milling; and last, suction erosion treatment is performed, and finally the micro-doped high-surface-area nano-zirconium dioxide powder is obtained. The method has the advantages that component control precision is high, technological stability and repeatability are strong, and the surface area and mobility of zirconium dioxide can be realized.