The present invention relates to a quinazoline derivative shown in formula (I) and a preparation method therefor, a pharmaceutical composition comprising the compound shown in formula (I), and an application of the compound in preparing drugs for curing and preventing tumors. The compound of the present invention can irreversibly prevent EGFR phosphorylation, and effectively depress signal transduction of cancer cells, and accordingly has higher anti-tumor activity in vitro and in vivo.