The invention discloses a benzo-azepine type derivative and a preparation method and purposes thereof. The benzo-azepine type derivative has the structure of a general formula I, wherein in the formula I, R1 is any one among hydrogen, halogen, or halogen substituted C1-C4 alkyl, R2 is oxygen or hydroxyl, and R3 is any one among hydrogen, C1-C4 alkyl, C1-C4 alkoxy, halogen or hydroxyl. According to the invention, compounds or pharmaceutically acceptable salts having the structure of the formula I are novel in chemical constitution, and have an obvious restraining effect, the same as fluorouracil generally used in clinical trials, for tumors, in particular to human lung adenocarcinoma cells, human breast cancer cells and human gastric carcinoma cells.