The invention relates to substituted benzamide compounds shown as a general formula (I) or medicinal salts thereof, preparation of the compounds or the medicinal salts thereof, a medicament composition containing the compounds or the medicinal salts thereof and application of the compounds in treatment of cancers, in particular application in treatment of head and neck cancers, non-small cell lung cancer, pancreatic cancer, colorectal cancer, bladder cancer, breast cancer, ovarian cancer and flat cell cancer and application in medicaments for treating the cancers.