The present disclosure provides a method of preparing a microporous ceramic membrane by forming a uniform microporous structure in a ceramic layer by a mild reaction between an organic acid and a carbonate or bicarbonate, thereby preparing the microporous ceramic membrane. The microporous ceramic diaphragm prepared by the method of the invention improves the permeability, facilitates the transferof lithium ions, reduces the formation of lithium dendrite caused by the enrichment of lithium ions in the process of charging and discharging at a high rate, and improves the cycling performance andsafety performance of the lithium ion battery.