Prussian blue analogue Ce[Co(CN)6]·nH2O nanoparticles were prepared by water bath coprecipitation for the first time. The effects of reaction parameters on the morphology and particle size of the synthesized products were revealed by controlling the variable method. The synthetic product has the characteristics of simple preparation method, low cost, small particle size and MOF (Metal organic framework). The cerium and cobalt elements contained in it are common catalytic active elements, which provides ideas and reference for the design and preparation of high-efficiency and low-cost catalysts.