A preparing method of porous ceramic and the porous ceramic prepared are disclosed. The method includes: dissolving an organic polymer into at least two solvents with different degrees of solubility to prepare a uniform single-phase solution or a separated two-phase solution; uniformly dispersing ceramic powder into the organic polymer solution to prepare ceramic slurry; precipitating the organic polymer, heating and evaporating all the solvent after a flocculent porous structure is precipitated so as to form a ceramic green body in which the organic polymer is uniformly distributed; heating continuously to burn off the organic polymer so as to form a porous ceramic green body; and sintering at a high temperature to form the porous ceramic. According to the method, the connectivity among micropores is high; and by controlling the using amount and precipitation of the organic polymer, the size and distribution of the micropores can be controlled, and a ceramic product with high porosity can be prepared. The method has characteristics of simple and convenient operation, cheap and easily available raw materials, no need of special equipment, environmental friendly production and no pollution, and is especially suitable for large-scale production.