In this paper，ten novel 2-ester polycyclic fused 1, 5-benzothiazepine compounds were obtained via one-pot three-component tandem reactions with CeCl₃ as catalyst in ethanol. These reactions were achieved by reacting substituted o-aminothiophenol，substituted 1indanone，ethyl glyoxylate.The reaction process was the Knoevenagel reaction between substituted 1-indanone and ethyl glyoxylate to require α, β-unsaturated ester compounds without separating intermediates.the aminoketone intermediate was formed by the conjugate addition of the nucleophilic sulfhydryl group on o-aminothiophenol.Then, the polycyclic fused 1, 5-benzothiazepine compounds of imine or enamine structure were formed by intramolecular nucleophilic addition and dehydration cyclization that another nucleophilic amino group attacks the carbonyl group. The synthesis method abandons the traditional multi-step reaction and has the advantages of atomic economy，simple operation，mild reaction conditions，high yield，good selectivity and environmental protection, respectively.