The invention discloses maraniol with anticancer activity and a preparation method and application thereof. The maraniol is a diaryl heptane compound; the molecular formula of the maraniol is C20H24O4; and the chemical formula is shown in (I). As proved by in vivo and in vitro pharmacological activity researches, the compound has strong anticancer activity, so that a novel anticancer medicine which takes the maraniol as a raw material can be hopefully developed.