Provided in the present disclosure are a pharmaceutically acceptable salt of an epidermal growth factor receptor (EGFR) inhibitor, a crystal form thereof, a preparation method therefor and an application thereof. The structural formula of the EGFR inhibitor is as shown in formula I, and the pharmaceutically acceptable salt is a mesylate, p-toluenesulfonate, phosphate, hydrochloride or citrate salt of the EGFR inhibitor. The pharmaceutically acceptable salt of EGFR inhibitor of the present disclosure has a specific crystal form, has a higher solubility and stability than a corresponding free base, is more suitable for preparing drugs for use in treating cancer (especially non-small cell lung cancer), and satisfies the requirements for bioavailability and drug efficacy.