The invention discloses a 2,3,5-substituted imidazole[1,2-c]-thiophene[2,3-e]-7(8H)keto heterocyclic compound of which the structure is shown as a formula (I) shown in the description. The invention also discloses a preparation method of the compound and application of the compound in preparing antineoplastic drugs. The 2,3,5-substituted imidazole[1,2-c]-thiophene[2,3-e]-7(8H)keto heterocyclic compound provided by the invention adopts a two-step synthesis method, a one-pot reaction is adopted for forming two heterocyclic rings, the reaction material is easily obtained, the operation is convenient, the reaction condition is mild, the reaction time is moderate, the control is easy, the after-treatment is simple, the purity and yield of a product are high, and the compound and the synthetic method thereof have the advantages of being less in operation step, high in yield, free of reagents such as phosphorus, low in toxicity, convenient to operate and the like.