The invention belongs to the technical field of a functional nanomaterial, and relates to a metal oxide/graphene composite material and a preparation method and an application thereof. The preparationmethod comprises the steps of performing mixing and stirring on graphite, concentrated sulfuric acid and sodium nitrate, and weighing potassium permanganate to be added into the mixture to be stirredcontinuously; adding distilling water in ice-water bath to be diluted and stirred; adding a H<2>O<2> water solution and performing stirring; performing repeated washing by distilling water until a neutral state is achieved, and collecting a graphene oxide sample; and putting a metal element into the graphene oxide water solution, performing standing at the room temperature, then collecting a black solid product generated by washing, and performing freezing and drying to obtain a metal oxide/graphene compound. The method is simple and convenient in operation, mild in preparation conditions, low in cost and easily available in raw materials; the product, used as a negative electrode material of a lithium ion battery, has high electrochemical performance; and the composite material also canbe applied to the fields of a solar battery, a gas sensor, a light emitting diode, a laser diode, a supercapacitor, a spinning electronic device, an ultraviolet detector, a field effect transistor, photocatalysis sewage treatment and the like.