Disclosed are applications of substituent benzyloxy group containing ether compounds represented by general formula I for preparing antitumor drugs.The definition of the substituent groups in the formula I are provided in the specification.The compounds having general formula I have desirable antitumor activity, particularly, and have excellent activity against leukemia strain HL-60, lung cancer A549, H157, H460, H520, bladder cancer T24, J82, prostate cancer LNCap, PC-3, rectal cancer HCT8, HCT116, RkO and the like.