Preparation method of composite type positive electrode material for lithium battery

The invention discloses a preparation method of a composite type positive electrode material for a lithium battery. The preparation method comprises the following steps: ultrasonically dispersing graphene oxide into deionized water, adding cerium acetate, potassium acetate, urea and ammonia water into a container, and performing sealing, baking, drying and microwave treatment to prepare a cerium oxide/graphene compound; preparing rare earth metal ion doped lithium iron phosphate from raw materials such as lithium hydroxide, iron phosphate, oxalic acid, glucose and rare earth metal oxide; performing ultrasonic dispersion and ball milling on the cerium oxide/graphene compound, the rare earth metal ion doped lithium iron phosphate and ethanol to prepare cerium oxide/graphene rare earth metalion doped lithium iron phosphate; and performing stirring, microwave treatment and calcination on the raw materials such as the lithium hydroxide, ferric vanadate, phosphoric acid, deionized water andthe cerium oxide/graphene