The invention discloses a method for changing the alignment of benzophenanthrene type disc liquid crystal molecules. A template hydrothermal method is utilized to prepare the vertical structured and an ordered array of ZnO nanorods, 50 to 70 nm of that space exits between the nanorods, which is used as the alignment substrate of benzophenanthrene-like disc liquid crystal molecules, Benzophenanthrene-like disc liquid crystal are deposited on a ZnO nanorod array substrate by a spray method, a ZnO/benzophenanthrene type disc-like liquid crystal composite film is for, 8 DEG C above that clear point of benzophenanthrene liquid crystal molecule, the temperature constant is kept for more than 6 minutes, cooling is preformed, as such, that molecular orientation of the disc liquid crystal in the ZnO/benzophenanthrene-like disc liquid crystal composite film lay presents a vertical orientation with the molecular surface face upward, and the molecular orientation of the disc liquid crystal molecule in the ZnO/benzophenanthrene-like disc liquid crystal composite film lay is realized. The orientation method is simple and can form a uniform film with good quality in a short time without externalelectric field or precise temperature control, which promotes the application of benzophenanthrene-like disk organic molecules in OLED and OPV electronic devices.