The green synthesis of chloropropylene carbonate via the coupling reaction of carbon dioxide and epichlorohydrin had been achieved using halogen-free and single-component catalysts tetrabutylammonium salts of tritransition-metal-substituted A-α-tungstogermanate [(n-C4H9)4N]3H7GeW9M3(H2O)3O37 (M = CuⅡ, NiⅡ, CoⅡ and MnⅡ) without any solvent. The catalytic activity was significantly depended on the transition metal introduced in polyoxometalates. [(n-C4H9)4N]3H7GeW9Mn3(H2O)3O37 exhibited the highest catalytic activity with 94.9% conversion for epichlorohydrin and 98% selectivity for chloropropylene carbonate in 3 h. Plausible mechanism was proposed based on the results.