a method for preparing polyether glycol is disclosed . an ester end - capped polyalkylene ether and an alcohol are subjected to alcoholysis at a temperature of 35 °- 150 ° c . and a pressure of 1 - 10 atm in the presence of a mixed metal oxide as a catalyst . the mixed metal oxide includes an alkaline earth metal oxide and at least one component selected from alumina , silica , and zinc oxide .