Disclosed are a serious of 2′,5′-dimethoxychalcone derivatives for treating cancer, wherein 2,5-dimethoxyacetophenone and methyl 4-formylbenzoate are condensed to form 4-carboxyl-2′,5′-dimethoxychalcone (compound 1), which is further reacted with alkyl halides or amines to synthesize the chalcone derivatives of compounds 2-17. In addition, 2,5-dimethoxyacetophenone is reacted with 5-formyl-2-thiophenecarboxylic acid to form compound 18 (3-(3-thiophene)carboxyl-1-(2,5-dimethoxyphenyl)prop-2-en-1-one). The synthesized 2′,5′-dimethoxychalcone derivatives can be acted as microtubule-targeted tubulin-polymerizing agents.