The invention provides a method for preparing continuous single-layer graphene on an insulation substrate. The method comprises the following steps of (1) providing the insulation substrate, and depositing a germanium thin film on the insulation substrate; (2) using the germanium thin film as a catalyst, growing graphene at high temperature, continuously evaporating the germanium thin film at high temperature at the same time, and finally removing the whole germanium thin film, so as to obtain the continuous graphene which is combined onto the insulation substrate. The method has the advantages that the graphene is catalyzed to grow by the germanium thin film on the insulation substrate, and the germanium thin film is evaporated to remove in the growth process, so as to obtain the single-layer continuous graphene on an insulator; the influence of pollution, wrinkle and the like due to preparation of the graphene on the insulator by a transfer method in the traditional technology is avoided; the quality and property of the graphene material on the insulator are improved; the large-area single-layer continuous graphene can be obtained; the steps are simple, the effect is obvious, and the wide application prospect is realized in the field of graphene preparation.