NOVELTY - Preparation of graphene-quantum dot compound film comprises diluting graphene-quantum dot solution, stirring, vacuum filtering graphene-quantum dot suspension liquid, forming film on unprocessed filtering film; or vacuum filtering suspension liquid of oxide grain, depositing layer of oxide film on unprocessed filtering film, filtering graphene-quantum dot suspension liquid, depositing to processed filtering film, washing with water, fixing film tightly connected to filtering film to substrate material, drying, and using acetone to dissolve filtering film.    USE - Method of preparation of graphene-quantum dot compound film used for constructed solar battery (claimed).    ADVANTAGE - The constructed battery has low cost, simple manufacturing technique, low temperature and stable performance; and the graphene-quantum dot film prepared can improve photoelectron transmitting performance and improve photoelectrical transfer efficiency of the battery.    DETAILED DESCRIPTION - Preparation of graphene-quantum dot compound film comprises:    (A) using natural graphite powder as raw material, adding (g) sodium nitrate (0.1-5), cold concentrated sulfuric acid (10-100) and potassium permanganate (0.5-10), uniformly mixing at less than 20 degrees C, heating at 30-40 degrees C, reacting for 25-35 minutes, slowly adding deionized water to mixed solution for dilution, heating at 95-100 degrees C, reacting for 10-20 minutes, adding hydrogen peroxide solution (5-50 ml), centrifugally filtering solution, using diluted hydrochloric acid to wash and remove metal ion, using deionized water to wash and remove residual acid, using water to wash until neutral, obtaining aqueous solution of oxidized graphite sheet, and ultrasonically treating to obtain fulvous uniformly dispersed oxidized graphene solution;    (B) taking uniformly dispersed oxidized graphene solution, adding quantum dot grains or quantum dot reaction precursor to form oxidized graphene-quantum dot mixed solution at mass ratio of 1:1-1:50, adding reducing agent hydrazine hydrate to oxidized graphene-quantum dot mixed solution, stirring for 24 hours at 80 degrees C, passing through reduction reaction, ultrasonically treating obtained product, centrifugally removing precipitate and centrifuging, with obtained stable suspension liquid as graphene-quantum dot solution;and    (C) diluting graphene-quantum dot solution, stirring until uniform and stable suspension liquid is formed, vacuum filtering graphene-quantum dot suspension liquid, and forming film on unprocessed filtering film; or vacuum filtering suspension liquid of oxide grain, depositing layer of oxide film on un-processed filtering film, filtering graphene-quantum dot suspension liquid, depositing to processed filtering film, washing with water, fixing film tightly connected to filtering film to substrate material, putting to drying box to dry with vacuum for 6-24 hours at 55-65 degrees C, and using acetone to dissolve filtering film to obtain film with graphene-quantum dot on conductive substrate.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of the graphene-quantum dot compound film.