The present disclosure relates to the field of catalyst preparation, and more particularly to a composite catalyst for catalyzing polymerization of cyclic ethers, a preparation method and a use thereof. The method includes the following steps: (1) dissolving a metal salt in a solvent, stirring evenly to obtain a first component; (2) adding a silicon source to the first component, reacting the silicon source and the metal salt, and standing; (3) removing the solvent, drying, to obtain a dried powder; (4) calcining the dried powder to obtain the composite catalyst. The composite catalyst prepared by the present disclosure has suitable acidity, and has acid sites of Lewis acid and Bronsted acid at the same time. The composite catalyst can show suitable acidity through the combination of two acid sites, to achieve higher conversion rate and narrower molecular weight distribution in the ring-opening polymerization reaction of cyclic ethers.