Disclosed are a 4-sulfur substituted podophyllotoxin derivative and a synthetic method therefor and the use thereof. In the present invention, introducing heteroaromatic compounds with rigidity, such as 4-trifluoromethylpyridin-2-thiol, 4-trifluoromethyl-2-mercaptopyrimidine, and para-fluorothiophenol, respectively as substituent groups to position 4 of C ring of a podophyllotoxin or 4demethylepipodophyllotoxin, obtaining a podophyllotoxin derivative as shown in formula (V) with a significantly improved antitumour activity and reduced toxic side effects. Experiments of in vitro tumour cell activity inhibition indicate that the antitumour activity of the compound as shown in formula (V) of the present invention is significantly improved compared to that of the podophyllotoxin or 4demethylepipodophyllotoxin.