The invention discloses an ester-exchange-reaction catalyst, as well as a preparation method and an application thereof. The catalyst comprises a catalytic active ingredient containing potassium oxide-calcium oxide composite oxide and a porous oxide forming binder with the specific surface area being between 50m<2>/g and 230m<2>/g, wherein the mass ratio of potassium oxide to calcium oxide to the forming binder is between (0.05-0.25) to 1.0 to (0.2-0.8). The preparation method comprises the following steps: (1) uniformly dispersing a potassium oxide precursor, a calcium oxide precursor and forming binder powder in water with the mass ratio of potassium element to calcium element to the forming binder being (0.06-0.3) to 1.0 to (0.3-1.12); (2) adding auxiliary agents, uniformly mixing, drying and grinding; (3) adding a forming additive, forming and drying; and (4) roasting for 3-8 hours. The catalyst disclosed by the invention is high in catalytic activity, good in anti-inactivation property, simple in preparation and low in cost and can be applied in synthesis of polyalcohol carbonate ester.