Disclosed are a gem-difluoroethyl substituted stilbene and diphenylethane derivatives, and a preparation method therefor and the use thereof. The present invention conducts a chemical structure modification with a gem-difluoroethyl at the 4' position of the B-aryl ring of diphenylethane/stilbene, and the 2' position thereof is modified into a substituent such as a nitro or amino. The gem-difluoroethyl substituted stilbene and diphenylethane derivatives have strong anti-tumour activity in vitro, with the anti-tumour activity of the trans-structure thereof better than that of the cis-structure thereof, and with the introduction of a fluorine atom not only changing the physical properties of the compounds themselves but also enhancing the anti-tumor activity in vitro, and have a good inhibitory effect on a variety of tumour cells. (I)